Teacher’s Guide Contents Introduction

How does this kit work? ............................................................................................... 2

Curriculum Links ............................................................................................................ 3

Module 1 – Properties of Water

Activities

1.1) Colouring Celery ..................................................................................................... 4 1.2) Unbreakable Balloon .............................................................................................. 7 1.3) Experimenting with Temperature ........................................................................ 10 1.4) Floating Coins ....................................................................................................... 13 1.5) Pepper-trified Water ............................................................................................ 16 1.6) Water, Steam or Ice? ............................................................................................ 18 1.7) Distillation of Fruit Juice ....................................................................................... 22

Module 2 – Water for Life

Activities

2.1) All Dried Out ......................................................................................................... 26 2.2) Billabong Bugs....................................................................................................... 31 2.3) Growth Games ...................................................................................................... 34

Module 3 – Environment and Conservation

Activities

3.1) Mini Water Cycle .................................................................................................. 37 3.2) Water Purification ................................................................................................ 41 3.3) How “Flow” Can You Go? ..................................................................................... 46 3.4) Water, Water Everywhere and Not a Drop to Drink ............................................ 49 3.5) Build your own Aquifer ......................................................................................... 52

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How does this kit work?

This guide has been designed and written to help you, as the educator to confidently conduct exciting, interactive and engaging science lessons.

There are three topics in this DIY kit; Properties of Water, Water for Life, and Environment and Conservation. Within each topic are several different activities that are suitable for Years 4-7.

You’ll notice that each activity has been written similarly to a science report. You can use this style to help the students write out their own scientific report if you wish. The information contained in this guide is designed for you to use and not the students.

The duration of each activity is purely an estimate and you as the educator should read the activity first to ascertain a suitable length of time to spend for each. You will also need to factor in enough time to sufficiently wrap up and discuss each experiment.

Extension activity suggestions have been made at the end of each activity. Please note that these are not included in the duration time and the equipment required has not been provided. These activities can be carried out if the students require any extension or can be suggested for them to try at home.

Many of the activities utilise easy to gather materials. While we have supplied many of the materials, you may like to source some of your own as well to give the class the opportunity to work in smaller groups.

Please note that many of these activities are designed to run over a couple of lessons, sometimes overnight, sometimes with up to a week in between. Make sure you account for this when planning your classes.

Equipment:

The numbers of the various items included in the kit were designed for use with a class of 32 students. Due to weight, size and cost limitations, most of the activities require the students to form pairs or small groups to carry out the activities.

Although the kit contains a large number of items (a checklist of all the contained items was included with the folder), some items have not been included in this kit which you will need to supply for various activities. These items include:

Water for all activities

Celery Stalks

Fruit and Vegetable Samples

Fruit Juice

3L Pure Drinking Water

Sample of dirty water

Drinking cup

2L soft drink bottles, cut in half – optional

Pencils

Large Saucepan and Lid

Small containers appropriate to grow seedlings in

Soil

White sand

Bucket

You will also require access to a freezer and tap with a hose.

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Student Worksheets:

These worksheets do not need to accompany each activity. You may like to encourage the students to use their own workbooks or display the information in a different way. Students should be encouraged to think about each activity and discuss a potential method to test their ideas and hypotheses. You can use the student worksheets to write down these ideas.

Curriculum Links:

The activities contained in this Water DIY kit have been designed to fit with the Australian National Curriculum. Specific links are shown at the start of each activity.

Science inquiry skills and science as a human endeavour are core to the design of these kits and are embedded in each activity.

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Activity 1.1 – Colouring Celery

Aim

To explore how water is transported in plants.

Curriculum Links

Year 5 & 6 Biology

Year 6 & 7 Earth and Space

Objectives

To build the students’ understanding of the scientific method and enhance their science

inquiry skills.

Duration

Discussion and initial set-up time: 40 minutes

Experimental time: 2 hours to overnight

Safety and Disposal

No special procedures needed however food colouring is not to be ingested. Rinse mouth with

water and seek medical attention if any symptoms appear upon ingesting any food colouring.

Due care should be taken when working with the vegetable peeler and knife. It is

recommended that the teacher or other responsible adult use these and not the students.

Materials

Celery stalks

Water

Food colouring

Plastic cups

Vegetable peeler

Chopping board

Knife

Masking tape

Plastic spoons

5

Method

1. Introduce the activity to the students and state the aim. Allow the students to familiarise

themselves with the materials that will be provided. Encourage the students to make

suggestions about how the celery stalks can change colour.

2. Plan the experiment with the students (you can use the following steps as a guide).

3. Encourage the students to make a prediction about what they think will happen. Write it

down.

4. Divide the class into groups. Provide each group with a celery stalk.

5. Providing guidance and supervision allow the students to set-up their experiment as per

their plan. Alternatively, follow the next set of instructions to carry out the activity.

6. Start by cutting the pieces of celery to same length, making sure to remove the white part at

the base of the stalk. The leaves can be left on top.

7. Fill each of the plastic cups with water to the same level and add 1 teaspoon of food

colouring to each. Each group may like to label their cups using masking tape.

8. Place the celery stalk in to the plastic cup being careful not to tip it over. It may need to rest

up against a wall.

9. Leave the stalks in the water for intervals of 2 hours, 4 hours and overnight

10. Carefully use the vegetable peeler to peel back the flesh on the round side and encourage

the students to observe how far the water has travelled up the celery stalk at the end of

each time interval. Replace the celery back in to the water to continue the experiment. The

students should record these results. A drawing or photograph may also accompany their

written observations.

11. With guidance from the scientific explanation below, discuss the results with the students

and allow them to compare their predictions with the actual result. Encourage questioning

to discover why and how things happened. If appropriate, ask the students to re-design the

experiment to test different things.

Extension Activity

After completing the initial investigation, encourage the students to discuss the experiment, their

predictions, what was tested and the results. They should recognise that there are variations of this

experiment that can be used to test different things. Students may like to discover what might

happen if the celery stalk was partially cut and each “foot” placed in different coloured water. Or,

does adding salt or sugar to the water change the rate at which the colour is taken up? How does

the rate the colour is absorbed change if the celery is soaked in water before hand? How would you

test this? Can you make the basic process of transpiration occur at a faster rate? Does the rate of

transpiration change if the stalks are left in the dark? Does the celery feel any different after the

experiment? What happens when you use white flowers (like carnations) instead of celery?

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Explanation

Just like humans, plants need water for survival. Plants get their water from the soil through a

process known as transpiration. Transpiration involves the loss of water vapour from the plant’s

leaves and even a little from their flowers, stems and roots. Similar to humans sweating, plants use

transpiration to cool down as well as allow the flow of nutrients from the ground to its leaves. As the

plant starts losing water from its upper reaches it causes a pressure difference which effectively

pumps more water from the ground. A process known as capillary action assists this to occur. The

plants use special capillaries or tubes known as xylems to carry the water. It is the xylems that you

can see taking up the coloured water. Capillary action works because water is attracted to itself. The

individual H2O molecules stick to themselves, known as cohesion, and stick to the xylems within the

celery too, this is known as adhesion.

These two processes work together so that effectively the molecules of water “climb” up the stick of

celery. Capillary action is driven by transpiration as it causes a pressure change allowing the water to

overcome gravity and be drawn up through the xylems to provide nutrients for the entire plant. As

transpiration is similar to evaporation, it occurs as a much faster rate in warmer weather, and why

plants are more prone to drying out during the summer months.

Real World Relevance

Capillary action can be seen in lots of different places. When you spill something and try mopping it

up with a sponge or paper towel you can observe the liquid moving from the spill in to the cloth

without you having to do anything. As water is attracted to itself, it uses its cohesive and adhesive

forces to climb through the cloth just like it did with the celery stalk!

The human body uses capillary action as well. Our blood is made of up approximately 80% water and

is able to carry nutrients and oxygen around our body. The water inside our bodies also functions as

a waste remover and can carry toxins and other waste away from the cells. This is done through

capillary action.

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Activity 1.2 – Unbreakable Balloon

Aim

To demonstrate the heat capacity of water.

Curriculum Links

Year 4 & 5 Chemical

Year 5 Physical

Year 6 Earth and Space

Objectives

To conduct a fair test exploring the heat capacity of water. Students should recognise and

suggest safe ways to use the materials, identifying potential risks. Presented with the given

materials, students should make predictions as to what they expect to happen. They should

compare the result with their predictions and use this as evidence to develop a scientific

explanation.

Duration

Discussion: 10 minutes

Demonstration time: 10 minutes

Safety and Disposal

Safety glasses for the demonstrator. The students should be seated 2 metres away. Due care

should be used by the demonstrator when applying the lighter to the bottom of the balloon.

None of the students should be allowed to apply the lighter to the balloon.

Materials

2 Balloons

Wooden stick with slit in it

Lighter

2 Safety glasses

Water

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Method

This is a teacher led demonstration. Do not let students use the lighter themselves.

It is suggested to test the demonstration prior to showing to the children.

This activity is designed to be followed by the next activity “How hot is that?” where the students

can further explore heat capacity.

1. Introduce the activity to the students and state the aim. Encourage the students to think

about what “heat capacity” actually means throughout the demonstration.

2. Blow up one balloon with air, fill the other with water until it is approximately the size of a

soft ball. Allow the students to predict what will happen when the lighter is applied the each

balloon.

3. Wearing the safety glasses, attach the air-filled balloon to the wooden stick, and holding at

arm’s length apply the lighter to the bottom of the balloon, or have a student (who is not

afraid of the balloon popping) hold the balloon at arm’s length while an adult applies the

lighter. Observe what happens.

4. Now, swap balloons and repeat with the water-filled one carefully applying the flame to the

underneath of the balloon for approximately 5-10 seconds. Observe what happens.

5. Discuss the results as a class and formulate a scientific explanation to explain heat capacity.

Compare this to what the students thought earlier.

Extension Activity

After completing the initial demonstration, encourage the students to discuss what heat capacity

means. What does this experiment tell about heat properties of air and water? Predict what would

happen if the amount of water in the balloon was increased or decreased? Would more water

absorb more energy? Design an experiment to test this. What variables need to stay constant and

which ones need to change? Could different heat sources be used (sun light, magnifying glass)?

How could the results of this experiment be applied to the environment/ the earth? How could this

knowledge be used to make the world a better place? What could you make with this technology?

Explanation

Water has a high heat capacity. This means water can absorb a lot of energy (heat) without its

temperature changing significantly. It takes a lot of energy to change the temperature of water,

hence the unusually high boiling temperature of water compared to other liquids. When a flame was

placed on the air-filled balloon only air was there to absorb the heat and, the rubber burnt and

popped. When the flame was placed on the water-filled balloon, the water absorbed the heat of

the flame, keeping the rubber of the balloon cool and preventing it from popping.

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Real World Relevance

The oceans help the earth stay cool by absorbing energy (heat) from the air and sun just like the

balloon. As the amount of water increases so does the quantity of energy that can be absorbed

without increasing the temperature of the water. An example of this effect can be seen by

comparing coastal and inland temperatures under simular weather conditions. In general the coast

will be cooler because a large amount of the heat energy is absorbed by the water.

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Activity 1.3 – Experimenting with Temperature

Aim

To investigate the heat capacity of air and water

Curriculum Links

Year 4-6 Chemical

Year 5 Physical

Year 6 & 7 Earth and Space

Objectives

Students should identify questions and problems that can be investigated scientifically and

make predictions based on their scientific knowledge. Students should plan and conduct the

investigation. Tools should be used safely to record and measure their results. The data and

results should be represented scientifically using graphs and/or tables. Students should

reflect on the investigation and communicate their findings. Encourage the students to

recognise what their findings could mean for the world around them.

Duration

1.5 hours

Safety and Disposal

Due care should be taken to not break the thermometers.

Materials

Digital Thermometers

Worksheet

Pencils

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Method

This activity is designed to be a continuation of the Unbreakable Balloon demonstration.

1. Briefly review the “Unbreakable Balloon” demonstration and ask the students to explain

what “heat capacity” means and its relevance to water.

2. Introduce this activity to the students and state the aim. Allow the students to ask

questions, identify problems and plan their scientific investigation in small groups.

Encourage the students to write down a prediction or hypothesis stating what they expect

this investigation to find. Assist this by providing them with a range of options to test

including location, vessel size and time of day.

3. Gather the materials needed to conduct the investigation. Ensure the students understand

how to safely use the thermometers.

4. In groups allow the students to explore various locations around the school grounds or in

surrounding areas (under supervision) to measure the temperature of water and air using

the thermometers. Try to pick locations that have different environments. While the

thermometers equilibrate (this may take a couple of minutes) with the unique temperature

at each site ask the students to record their observations for the location (surroundings,

colours, shade, sunlight).

5. As a whole class, log the results and observations on the worksheet. It might be helpful to

make a big chart to hang up somewhere. Discuss what could account for the differences.

Extension Activity

What could account for the differences in water and air temperature in the different locations? Is it

possible to predict the temperature of water and air based on the surroundings? If the site receives

direct or indirect sunlight does this make a difference? Is there a difference in temperatures

between areas with light colours and dark colours? How about between water on the ground and in

a birdbath or higher up off the ground? Did the temperature of the water depend on the size of the

pool of water? Do different building materials affect the temperatures? How could you create an

object that would heat up water or keep it cold? Use your new knowledge to design something to

keep an ice cube alive the longest in a cup of water. Did the temperature of an object affect its

physical properties? Make a birdbath that will stay cooler longer with your new knowledge.

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Explanation

The difference in temperature has several different causes. The first of which is that water has a high

heat capacity. In order to increase the temperature of water an enormous amount of energy (heat)

is required. The amount of energy needed is directly proportional to the amount of water that needs

heating. That is why smaller pools were hotter than larger bodies of water in this investigation.

The geography around you can also affect the temperature of the air and water around you.

Heat rises too which is why valleys are cooler than hills on hot days. The colour and material of the

surrounding environment can also affect the temperature. In general, dark objects absorb and hold

on to energy (heat) better than lighter coloured objects. This can be observed in the different

maximum temperatures of bitumen and cement on a hot day and how long they take to cool down

after the sun sets.

Real World Relevance

Water’s amazing heat capacity allows the oceans to regulate temperature changes. If you compared

the temperature on two identical days, on the coast and inland, you would find that the coast would

be cooler. The ocean is acting like a giant heat sink absorbing a lot of energy that would otherwise

heat up the air.

Ever noticed that the top layer of water is warmer than underneath when you step in to a pool?

Due to water’s heat capacity it takes a lot of energy over a long period of time to heat up large

amounts of water.

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Activity 1.4 – Floating Coins

Aim

To explore the surface tension of water.

Curriculum Links

Year 5 Biology

Year 4 and 5 Chemistry

Objectives

Students will recognise that water has special features that other living things can use for their

environment. Students should understand the surface tension of water and consider how this

can be useful to our lives.

Duration

30 minutes

Safety and Disposal

No special procedures needed

Materials

Plastic cups filled with water

Aluminium coins

Detergent

Pasteur pipettes

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Method

This experiment can be done as a challenge to learn about the surface tension of water. The

“challenge” is to get as many coins to float on the surface of the water. First get the students

to predict whether they think the coins will float at all. Allow the students to discuss how

floating might be possible and predict how many coins they will be able to float. You may

like to offer a prize for the person who can place the most coins on the water’s surface.

1. Firstly, fill the cups with water and place them on a flat surface so the water is still

2. Experiment with the metal coins to see if the students can get them to float on the surface

of the water. Encourage the students to record their observations.

3. Once the students have discovered how to get the coins to float, allow them to predict and

experiment with how many drops of water can be placed on the surface of each before it

sinks. Use the Pasteur pipettes.

4. To complete the experiment, ask the students to predict what will happen if a drop of

detergent is placed on the surface of the water. Now add a drop of detergent to the water.

Observe what happens.

Students will discover that by placing the items gently and horizontally on the surface of the water

they will float. If they put them in length ways they will sink.

Extension Activity

Have you even done a belly flop before? Do you know why it hurts so much? How about a dive? Encourage the students to use their knowledge of surface tension to discover why doing a belly flop hurts but a dive does not. An extension of this activity is to fill a cup up almost to the rim with water. Have the students add additional water drop by drop and see if they can get a dome of water to form above the lip of the glass. What happens if you poke it with the tip of a pencil?

15

Explanation

Notice that there is a thin membrane of water on the surface where the items are floating.

Ask the students to get down to eye-level with the cup to observe the water curving up at the edges.

The surface of the water allows the items to float on its surface through a process called surface

tension. If the items are placed in a way that breaks the surface tension they will sink to the bottom.

This is why you can float a coin when you place it on the face but not on its edge.

Surface tension is caused by interactions between water molecules. Each water molecule is made up

of two hydrogen atoms and one oxygen atom. The hydrogen atoms are attracted to the oxygen

atom in a different water molecule resulting in a loose net of molecules attracted to each other.

A good way to think about this is the game “British Bulldog”. In this game a line of children hold

hands while another child runs at them to try and break through the chain. You can think of the

children holding hands as the hydrogen bonds and the child running at them as the coin. If the child

running did not break through the chain, the hydrogen bonds held and the coin floated. However if

the child running broke through the chain, the coin sank because the hydrogen bonds were not

strong enough to support the coins weight. This is what happens when detergent is added to the

water. Adding detergent to the water breaks the hydrogen bonds that form between water

molecules therefore lowering the surface tension. In our game metaphor, adding the detergent has

a similar effect to two children holding hands with sweaty palms.

Real World Relevance

Water striders are small insects that use water’s skin (surface tension) to literally walk on water!

They have special feet that help to repel the water allowing them to float and move easily.

Lily pads float on the surface of the water in a similar way. The root systems of these plants do not

need to anchor the lilies as they are floating on water’s skin. The surface tension is so great that

even birds can land on the lily pads without breaking the surface tension and sinking the lilies.

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Activity 1.5 – Pepper-trified Water

Aim

To investigate the surface tension of water.

Curriculum Links

Year 5 Biology

Year 4 – 7 Chemistry

Objectives

Students will recognise that water has special features that other living things can use for their environment. Students should understand the surface tension of water and consider how this can be useful to our lives.

Duration

30 minutes

Safety and Disposal

Ensure the students wash their hands upon completing this experiment and do not allow them to put their hands in their mouth before they do so.

Materials

Plastic cups

Pepper

Detergent

Method

This activity is designed to be a continuation from the “Coin Floating” activity.

1. Review what was learned during the “Coin Floating” activity. What is surface tension? How

do we know it is there? Why is it useful?

2. Introduce this experiment as a challenge to break the surface tension of the water and

discover what happens. Can the students remember a way that the surface tension can be

broken? What is the scientific explanation behind it?

3. Fill the cups with clean water and place on a flat surface so the water is still.

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4. Sprinkle enough pepper over the cup so it lightly covers the surface of the water.

Allow the students to observe the pepper resting on the water. They may like to get

down to eye level to do this.

5. Predict what will happen when detergent is added to the water? What will it look like?

Why will this happen?

6. Allow the students to dip the very tip of their finger in to some detergent and place it gently

on the top of the water in the middle of the cup.

7. Observe what happens

Extension Activity

We have seen how detergent can break surface tension and cause all of the pepper to fall. Can you think of any way to use detergent’s ability to move a boat made out of a piece of paper/cardboard across water? What materials would you need to test this? What happens if you placed a drop of soap on the back side of a piece of cardboard? How about if you cut V in the back of the cardboard and placed the soap in this V? Experiment with other shaped cuts and see what happens.

Explanation

Just like in the previous experiment, the pepper lies on the surface of the water due to its surface

tension. Adding detergent breaks the surface tensions by disrupting the hydrogen bonding. This

means the pepper can no longer rest on the water’s surface and consequently sinks to the bottom.

The piece of cardboard with a cut out V in the back uses the detergents ability to break water

surface tension to power it across the bowl of water. Detergent breaks the hydrogen bonds at the

back of the boat only. This means that water’s attraction at the front of the boat is greater than that

at the back of the boat. The unequal attractive forces between the front and back of the boat results

in the piece of cardboard travelling forward.

Real World Relevance

Have you ever noticed that early in the morning the leaves are covered in small droplets of water?

These water drops form because of surface tension. Water molecules are more strongly attracted to

each other than they are to the waxy surface of the leaf. They would rather hold hands with each

other than with the leaf.

Similarly surface tension is the reason that rain falls in drops. The water that makes up raindrops

would rather be surrounded with other water molecules than by air. Spheres have the best enclosed

volume to surface ratio of all the different shapes so water molecules try and organize themselves

into drops. Can you imagine how much it would hurt to be hit on the head by little cubes of water

instead?

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Activity 1.6 – Water, Steam or Ice?

Aim

Explore the three different states that water can exist in.

Curriculum Links

Years 4-6 Chemical Science

Objectives

Students will recognise that water exists in three different states; solid, liquid and gas. Students will also discover that water exists in the air around us and be introduced to the water cycle.

Duration

1 hour

Safety and Disposal

Children should not operate, or touch the kettle at any time. It is hot and the kettle, the steam

and the boiling water are all burn hazards.

Do not ingest any water or ice used in this experiment.

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Materials

Water

Kettle

Metal trays (placed in freezer the night before)

Oven mitts

Glass jar/s with lid

Ice cubes

Paper towel

Spoons

Food colouring

Ice cube trays

Method

Before you start: pre-freeze coloured water in the ice cube tray and the metal tray the night before

the experiment is due to be carried out.

1. Start this activity by introducing the concept that water exists in three different states.

What does this mean scientifically? Where are some examples of different states of water in

your environment, and in the world around us? Allow the students to discuss ways in which

water can move through each of the states of matter. How can this happen? Introduce the

concepts of evaporation and condensation.

2. In small groups demonstrate the water cycle using the kettle and frozen metal tray. Observe

water in all three states; solid as frozen water on the tray, liquid inside the kettle, and gas as

the steam rising from the freshly boiling kettle.

3. Hold the tray over the steam rising from the kettle using the oven mitts. What is happening?

4. Encourage the students to write down their observations and discuss the explanation as a

class or in small groups. Students may like to complete the worksheet, making note of where

evaporation and condensation was occurring. The students have just observed a simple

water cycle. Ensure they recognise and understand this.

While the small groups are observing what is happening have the rest of the class further

investigate water in all three states.

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1. Review what the students have learned about the states of water and the water cycle.

Ask the students if they think there is water in the air? Let them predict how much water is

in the air. Do they think the environment has any effect on water content in the air?

What else is the air made up of?

2. Based on their knowledge, ask the students to plan an investigation to discover if water

exists in air. How will they test it? What will they need to do? The following steps can be

used to run this activity, or alternatively you may allow the class to carry out their own

experiments.

3. Fill the glass jar with coloured ice cubes

4. Screw on the lid and shake

5. Observe what is happening to the jar. Wrap the paper towel around the outside and

remove. Why is the tissue wet? Where does this water come from?

Extension Activity

Having completed the work sheet can the students explain the water cycle now? This could be

achieved as a class discussion. Can the students draw the water cycle in a different way (using

rainfall for example)? Students may like to explore how and why water takes up more space as a

solid. Is there a difference between the drip rates for hot versus cold water? How would you do this

experiment? What is the difference between the times it takes for water to freeze versus melting?

Does the environment affect this? Does the initial temperature of the water have any effect? Why?

Discuss how the environment can change the amount of water that is present in the air around us.

Could the students design an experiment to replicate different environments (such as humid versus

dry) and repeat this experiment? Discuss reasons why water might be an important component of

our atmosphere (particularly in regards to the water cycle). Leave the experiment running and

observe what happens to the ice cube inside the jar. Can the students recognise what is happening

and why?

Explanation

Water is the only substance that exists naturally on Earth in all three states; solid, liquid and gas.

When solid the water molecules are trapped together in a 3D grid pattern by strong intermolecular

bonds. This means that the molecules of water are stuck together and unable to move apart.

As solid water is heated its molecules gather more energy and start vibrating, with some of bonds

between the molecules breaking apart. When this happens the molecules can flow past each other

and take the shape of their container. In this liquid form the water molecules are vibrating in all

directions but do not have enough energy to vaporize and form a gas. We can change this by heating

the water. Eventually we will provide the water molecules with enough energy (heat) to turn in to a

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gas and all of the intermolecular bonds will have been broken. As a gas, the water molecules move

quickly in all directions and take up lots of space.

This experiment also demonstrates the water cycle. The metal tray cools the water vapour in the air

around it and may be observed as a cloud if it is cold enough. Boiling liquid water in the kettle

produces steam, or gaseous water that you can see rising from the spout of the kettle (known as

evaporation). As the steam hits the cool metal tray the gaseous water cools as well, slowing down

the movement of the H2O molecules and turning the water back to a liquid. You can observe this as

droplets of water on the tray (or condensation).

This is an example of how the water cycle works. On a simplistic level, liquid water is heated up by

the sun and evaporates as a gas in to the clouds. The clouds cool the gaseous water turning it back in

to a liquid and letting it fall back down as rain. On really cold days, solid water falls from the sky as

hail or snow, melting as it falls and hits the ground turning in to a liquid, before being heated up and

evaporated away again as water vapour to continue the cycle.

The amount of water in the air around us changes depending on the environment and the weather.

On humid days the concentration of water is greater than on dry days. Regardless of the weather

there is always some water that exists as vapour (or gas) in the atmosphere. When a gas is cooled it

turns in to a liquid. This process, known as condensation, is happening as the gaseous air from

around the room hits the sides of the jar, cools down, and turns into a liquid. This experiment allows

the students to observe that there is water in the air. The water can be collected using the tissue.

The students will also observe the solid water (ice cubes) being heated up by the surrounding

warmer air and it will turn in to a liquid. Left long enough and the students can observe the effects

of evaporation as the liquid water seemingly disappears as it turns in to a gas.

Real World Relevance

On a cold day what happens when you breathe out? The water vapour from your breath is cooled by

the air around you and clouds are formed in a process known as condensation.

On a hot day you probably sweat a lot more. Sweating is a way that the body can cool itself to stop

you from getting sick. Water from your body is released as sweat beads on your skin. These beads

evaporate off from the warmer air around you and turn in to a gas. Unfortunately on humid days

when there is lots of moisture (gaseous water) in the air your sweat stays on your skin and is really

uncomfortable!

This demonstration actually occurs in real life all of the time and is known as the Water Cycle.

Precipitation (or rain) falls from the clouds and gathers as ground water or surface run-off in our

oceans, dams, and lakes. As the sun heats it up it causes the water from plants and trees to

transpire, and the water from the oceans, dams, and lakes to evaporate. The water vapour that is in

the air cools and then condenses to form clouds before the water precipitates and falls down as rain

again.

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Activity 1.7 – Distillation of Fruit Juice

Aim

Explore the process of distillation and separate pure water from fruit juice.

Curriculum Links

Year 7 Chemical Science

Objectives

Students will be able to recognise and understand the concepts of solvent and solute(s)

in a solution, and will be able to perform the physical separation technique of distillation.

Students will identify a problem, and propose a way it can be scientifically investigated.

Using their scientific knowledge students will evaluate the process used and discuss ways

that it can be improved.

Duration

Introduction and initial set up time: 40 minutes

Experimental time: 15 minutes.

Safety and Disposal

Caution should be used when heating the set up on the stove and when handling the set up

after it has been removed from the stove.

Materials

Large saucepan with sloping lid

Ceramic coffee cup

Ceramic bowl

Ice

Electric stove top

Oven mitts

2 Beakers

Heat resistant mat

500ml of Fruit juice – highly coloured variety like orange, cranberry, grape juice

Ice cube trays

Weight

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Method

Before you start: pre-freeze some ice using the ice cube trays

1. Start this activity as a class discussion about water in drinks. Discuss ways that we know or

can prove that water exists in different drinks. Challenge them to separate water from a

particular drink (in this case fruit juice). Based on their existing scientific knowledge ask the

students to come up with ideas about how to accomplish this.

2. Introduce the key words of this activity; boiling point, phases of matter, condensation,

solvent, solute, distillate, and ensure the students understand them.

3. Allow the students to state the problem and guide them through the scientific process that

will be used for this activity. Ensure they understand the method before you start.

4. Encourage the students to predict what they think what will happen to the fruit juice during

the investigation. What will it look like, smell like, and taste like at the end? Let the students

investigate the properties of the juice before they start and have them record these

findings.

5. Use the following steps to carry out the experiment.

a. Set up the distillation apparatus as per the picture. Discuss with the students the

different parts and how it will work. Have they seen this before in the kitchen?

INSERT DIAGRAM

b. Pour the fruit juice in to the pot. Set aside approximately a cup full for comparison

later in the experiment

c. Place the ceramic coffee cup, right way up, in the centre of the pot so that it is

sitting in the juice. Place the weight in the cup.

d. Place the bowl on top of the cup so that it can catch the condensed liquid that drips

down from the lid. Place the lid over the pot, upside down

e. Put some ice in the lid of the pot, you’ll have to keep replacing the ice as it melts.

Ask the students why we need to add the ice.

f. Turn on the stove top and bring the juice to the boil. Turn down the temperature

and keep the juice simmering for approximately 10 minutes. What do you notice

happening on the inside of the lid? What is this condensed liquid? How do we

know?

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g. After approximately 10 minutes, or when you have collected enough distillate for

testing, turn off the stove and allow the set up to cool for 5 minutes. The distillate

can be found in the bowl.

h. Using the oven mitts, carefully remove the lid from the pot

i. Using oven mitts, lift the bowl off the cup and put it on a heat resistant surface

j. Using oven mitts, take the cup out of the pot

6. When the juice is completely cooled, pour it in to the clear beaker. Also, pour the distillate

into a clear beaker for comparison. Discuss with the students the differences between the

three liquids. How do their colours compare? Is one easier to pour and stir? What is each

liquid made of?

Extension Activity

Compare the original fruit juice to what is left in the pot and the bowl. Can the students recognise

what the distillate, the solvent, and the solute is? Investigate what has happened by comparing

colour, taste, smell and how easy it is to pour. What could account for these results? Students may

also like to try boiling each of the three different liquids and compare their boiling points.

Key Terms

Boiling point: the temperature at which liquid turns into vapour (gas).

Phases of matter: solid, liquid and gas.

Condensation: the process by which a gas changes in to a liquid

Solution: a mixture of two substances in the same matter phase, normally two liquids.

Composed of a solvent and at least one solute.

Solvent: a substance (usually a liquid) that is capable of dissolving another substance

Solute: a substance that is dissolved in the solvent creating a solution

Distillation: capturing the vapour that escapes from boiling a liquid and then cooling it

back to liquid

Distillate: the condensed liquid

Explanation

Distillation is a scientific technique that separates two liquids based on their different boiling points.

A liquid’s boiling point is the temperature at which the liquid turns to a gas. Scientists use this

difference to separate two liquids. This is done by heating the solution to one of the component

liquids boiling point. Normally, the liquid with the lowest boiling point is chosen. This ensures only

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one of the liquids are vaporised, allowing the pure vapour to be captured and condensed back into a

liquid for collection. Using this method, two liquids are separated from one parent solution. It is also

possible to carry out a distillation and end up with one liquid and one solid phase from a parent

solution, like in this experiment.

In this experiment we used basic distillation techniques to separate water from fruit juice. Fruit juice

is a solution in which the solvent is water and the solutes are the different sugars, flavouring,

electrolytes, and colours. Water has a lower boiling point than the solutes and therefore gets

transformed from a liquid to a gas at a lower temperature (earlier) and travels upwards towards the

inverted pot lid because hot gas rises. When the hot water vapour reaches the cold pot lid it

undergoes condensation. The freshly condensed water then rolls down the lid and drips into the

bowl where it is collected. As the water gets boiled off, the solutes get more concentrated because

there is less water for them to dissolve in. This increase in concentration of the impurities makes

the juice stickier and harder to pour.

Real World Relevance

The principle of distillation can be used to produce drinking water in places without access to safe clean water, such as India. Dirty water is collected and placed in a main pot that has a condenser (the pot lid) connected to a separate collection bowl (the bowl in the middle). The apparatus is then heated using the sun or a stove to boiling water. At this temperature the water molecules vaporize into a gas and travel up to the condenser where it is cooled back into its liquid form and collected as clean drinkable water. Most of the impurities such as germs and dirt are left in the bottom of the main pot.

Sea salt production also uses distillation, however in this case we are interested in what is left behind when water is vaporized. Sea salt is collected by flooding a shallow basin with sea water and allowing it to sit. Most of the water evaporates due to the sun’s heat leaving a concentrated solution of brine and mud. This solution is then collected, the mud washed off and the brine poured in to shallow trays. The trays can then be placed over a fire to vaporize the remaining water leaving behind pure sea salt.

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Activity 2.1 – All Dried Out

Aim

To determine how much water various common fruits and vegetables contain

Curriculum Links

Year 5 and 6 Biology

Year 6 and 7 Earth and Space

Objectives

Students will be able to identify plant adaptations that help them grow in different

environments. In addition, they will understand how changing environmental conditions can

affect plant growth. Specifically they will look at the water cycle and how it is affected over

time.

Duration

Initial discussion and set-up: 1 hour

Experimental time: overnight

Discussion and wrap up: 1 hour

Safety and Disposal

Caution must be exercised when peeling the food and cutting the food items into slices.

Please be mindful of potential food allergens when selecting your samples.

Materials

Fruit and/or Vegetable samples (see the Food Dehydrator instruction manual for appropriate

fruits and vegetables to use for your time constraints).

Food dehydrator

Electronic scale

Calculator

Vegetable peeler

Knife

Chopping board

Worksheet

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Method

It is best to leave the samples dehydrating over night. Therefore, it is recommended that the start of the activity be carried out towards the end of the school day and then completed first thing the next morning.

1. Start the activity with a class discussion about the water cycle and its role in plant growth and development. Discuss the different components of the cycle, and how plants take in and store water. What adaptations could plants use to store water during a drought? How do plants grown during a drought differ from ones grown with plenty of water? How could you measure how much water is stored in a plant?

2. Plan the experiment with the students (you can use the following steps as a guide).

3. Pass each fruit/vegetable around and encourage the students to predict which fruit/vegetable will contain the most water by listing each item in order of highest to lowest water content. Ask them to predict how long it will take to dehydrate each fruit/vegetable, and what adaptations could help keep the water in the longest? Write these down.

4. Weigh each sample and record its total weight. Peel, core and slice each sample to approximately 5mm thick. Weigh all slices and record the total weight of this sample. If using leafy vegetables pick a few leaves and weigh them.

5. Use the dehydrator to remove all of the water from your sample.

6. While waiting for the produce to dehydrate calculate what weight percentage of the total fruit/vegetable was placed in the dehydrator. Do this by taking the weight of the slice and dividing it by the total weight of the fruit/vegetable and multiplying it by 100.

(Slice weight) / (Total fruit weight) X 100 = % of total weight in the slice

7. Once the samples have been left for an appropriate length of time, remove them from the dehydrator and weigh them again. Note this down against the original weights recorded.

8. Determine the amount of water each fruit/vegetable contained by subtracting the ‘dehydrated’ weight from the ‘hydrated’ weight of each slice.

(Hydrated weight) – (Dehydrated weight) = Amount of water lost

9. Determine the percentage of water within each fruit/vegetable slice by dividing the ‘dehydrated’ weight by the ‘hydrated’ weight and multiplying the result by 100

(Dehydrated weight) / (Hydrated weight) x100 = % water in the sample

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10. Compare the water content of each fruit/vegetable by making a bar graph, table, or other kind of chart. You may like to use the activity sheet provided. For example:

11. Compare your results with the prediction you made at the beginning of the experiment. Were you able to guess which fruits/vegetables had the highest water content? Did you notice any features of the different fruit/vegetable skins and flesh that was different between the ones that lost the most and least water? What traits seemed to help the fruit retain water?

Fruit/Vegetable ‘Hydrated’ weight ‘Dehydrated’ weight Water content Percentage of

fruit/vegetable slice consisting of water

Apple

Banana

Strawberries

Green beans

Broccoli

Carrot

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Extension Activity

Try the same experiment using different plant items (leafs, bark, twigs, flowers) Which items lost the most water? What does this suggest about where plants store water?

Take identical slices of the same fruit and dip/brush with wax. Weigh these slices and then place in the dehydrator for the appropriate length of time. Weigh them again and calculate the amount of water lost. Which slices lost the most water? What did the wax do? Can you think of any plants that have a similar coating?

Rehydrate your samples. How much water do you predict they will need? How long should it take?

Explanation

All living things contain a high proportion of water and it is essential for their vital processes. In plants, water is needed to carry nutrients from the roots in the ground to the stems, leaves and in some cases fruits and vegetables growing from it. When a plant does not receive its required amount of water it becomes dehydrated and wilts. When plants become dehydrated the required nutrients are not as able to be pumped around and the plant may suffer or die.

Water makes up approximately 60% of your body. It has many important roles including removal of toxins from your body, carrying nutrients to your cells, regulating body temperature and providing a moist environment for your ears, nose and throat. It feels awful when you have a dry throat or mouth doesn’t it? Human beings are always releasing water from our bodies into the atmosphere around us. This is done through breathing, sweating, peeing and pooping. It is recommended that the average person drink between 6 – 8 glasses of water per day to prevent becoming dehydrated. Becoming dehydrated is dangerous because it can affect these important bodily processes. If you become sick, do lots of exercise or live in a different country/environment you may need to drink even more water to stop you becoming dehydrated. But, you don’t just get your water from drinking! Sometimes, we can eat it. Lots of fruits and vegetables contain large quantities of water. When you eat these foods your body takes up the water. Of course, eating fruits and vegetables not only gives you extra water, they’re also packed full of good stuff to keep your body healthy.

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Real World Relevance

In environments in which there is not a lot of rainfall such as deserts, animals tend to have adaptations that allow them to “drink an apple”. One example is Koalas. Koalas need to drink very little water as they get almost all of it from the eucalyptus leaves that make up their diet.

If you're eating dehydrated fruits or vegetables as snacks, you’ll need to consume more water to make up for the fact that you’re not getting any from the food, and you’re body is rehydrating them to help with the digestion process.

Dehydrating food is one of the oldest methods for food preservation. Even people in the pre-historic times were doing it! Using the sun or heat from a fire, or even salting methods could dry out meat, fruits and vegetables and help to keep them from going off so quickly.

Why is it so important that farmers get the rain? During a drought or poor rainfall season the farmer’s crops don’t receive enough water. When plants don’t receive enough water they don’t get the nutrients needed for good growth and survival. Even if the crop survives during a drought the quality won’t be as good and then the farmer won’t be able to sell it for as much.

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Activity 2.2 – Billabong Bugs

Aim

To understand the role water plays in the growth and reproduction of living things

Curriculum Links

Year 4-6 Biology

Objectives

Students will recognise that water is important for life and that all living things have features

to help them survive in their environment.

Duration

1 hour

Safety and Disposal

Billabong Bugs are non-toxic and do not bite or sting in any way

Materials

Billabong Bugs kit

o Thermometer

o Microscoop

o Bugditioner (water conditioner)

o Bugdust (egg/sand mixture)

o Bug Grub (food)

Desk lamp

3 litres of Nobles Pureau Pure Drinking Water (recommended brand) available from Coles,

IGA, or Woolworths

Clear tank

Tea spoon

Pasteur pipette

Magnifying glasses

Worksheet

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Method

The students should now have an understanding of why water is important for living things. This activity is about investigating how some organisms survive without water. Individually, or in small groups encourage the students to research organisms that do this. You may like to mention Triops australienis to give them some guidance with their research. What is so special about them? How do they survive without water? Why do they do it? When does water become a requirement? Collate the research as a class discussion. The students may also like to design posters or write a paper to present their findings.

If you haven’t already, introduce the Billabong Bugs to the students with a brief description of what they are and their history. Go online for more information. The students should understand what they are and have some understanding of how they will be grown and looked after.

As a class, follow the instruction in the Billabong Bugs Care Manual and watch for the hatchlings to appear. This should occur within 48 hours.

Set up a class roster outlining various tasks to be performed by different students on a day-to-day basis and at a nominated time. See if the students can come up with appropriate tasks and let them decide how often they should be done. These may include:

Counting the number of Bugs in the tank

Measuring the average size of the Bugs

Feeding the Bugs as per the instructions in the Care Manual

Removing leftover food from the tank

Monitoring the tank water temperature

Changing the tank water as per the instructions in the Care Manual

Monitoring the water level and topping it up as needed

Record all observations on a chart. The students may like to design it themselves. Discuss what would make an effective chart. What are they measuring or observing? How should this be recorded? This could be large and displayed in the classroom near the Billabong Bugs.

Guide the students in making a line graph to show the growth in the Billabong Bug population over time. Students might also plot a line showing the increase in Billabong Bug size over time. Are there different ways to present their other observations?

Extension Activity

Plant seeds are able to live without water for a period of time too. Students can design an experiment to test different plant seeds to see if they will germinate by adding water. What other factors could influence germination (heat, fire, smoke)? Can the students replicate a real-life scenario in the classroom? Why do plant seeds and organisms like Billabong Bugs need this adaptation? How has this been beneficial overtime?

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Explanation

Triops australiensis (also known as the Billabong Bug) is an outback Australian crustacean related to the now-extinct Trilobite and is older than the dinosaurs. “Triops” is Greek and literally means three eyes! Look closely to see if you can spot them. Billabong Bugs have very special eggs that can remain in “suspended animation”. Otherwise known as anhydrobiosis, organisms like the Billabong Bugs, plant seeds and even baker’s yeast undergo this process when faced with extremely dry conditions. This switches off the organisms ability to reproduce until their environment changes to become more favourable. In this case, replacing the water in the Billabong Bugs environment is enough to allow the eggs to hatch, the bugs to grow and reproduce.

Real World Relevance

Nearly all plants produce seeds that can be stored for some time before germinating. That’s why you can save seeds from your garden and plant them months or even years later. This property is being used by organisations around the world to create seed banks whose goal is to protect plant biodiversity. One of these projects is Millennium Seed Bank Project by the Royal Botanic Gardens in England. Seeds from all over the world are shipped to the gardens. At the gardens the seeds are cleaned, categorised and catalogued before being dehydrated and chilled to below 0 °C. After this the seeds are stored in a giant refrigerated warehouse.

A little bit closer to home Kings Park in Perth is the home of the WA Seed Technology Centre. Based at the Biodiversity Conservation Centre at the park, they are responsible for collecting seed and plant material, particularly endangered species, and storing it appropriately to ensure we have these plants for a long time to come. Seeds are dehydrated in a similar fashion and stored under anhydrobiotic conditions until required for germination.

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Activity 2.3 – Growth Games

Aim

To explore how watering strategies and plant selection affects growth in an Australian

environment.

Curriculum Links

Year 4 and 5 Biology

Objectives

Using the scientific method (asking questions, predicting, planning and carrying out

experiments) students will explore how the life cycles of plants can be influenced and

affected by water supply as well as fire and seed germination.

Duration

This activity can be broken into a “research” class and “experimental” class. Times taken will

be determined on an individual basis

Safety and Disposal

Please be mindful for potential allergens for some individuals. Hands should be washed

thoroughly after completing this experiment.

Materials

Various seedlings

Soil

Containers to grow the seedlings in

Spray bottles

Method

Introduce to the students the idea that there are native and non-native plants, water wise and non-

water wise. What does this mean? Students may like to do some research and provide examples of

each and even supply samples from their gardens.

Encourage the students to ask questions about the importance of plant choice for their garden at

home and/or their school. Why is it important to choose appropriate plants? What types of plants

are appropriate for your area? Let the students research this. Discuss watering restrictions. Why do

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we have them in Western Australia? What are they trying to achieve? What does this mean for us

and for the plants? How can we be more water wise?

This investigation will look into how different plants are affected by their environment and how best

to look after them. Using the supplied seedlings, or seedlings of your choice tell the students that

they will be designing an experiment to test how the environment affects the quality of plants. Give

them time to discuss, ask questions, make predictions, and plan an experiment to test one

environmental condition. This could include the time the plants are watered, the amount of water

they are provided with, sun/heat positioning, type of plant, or soil type and quality.

If appropriate, students should be encouraged to recognise the dependant and independent

variables and conduct fair tests to test their prediction. Students should record their observations

over a period of time.

Discuss what their results mean for this experiment, and for the environment. Can they relate this to

their everyday life? Is there a simple way that they can be more water wise at home, at school and

in the garden?

Extension Activity

Other countries and cultures use water and get water in lots of different ways. Can you research

some?

Can you do some research to discover what plants are most suitable at your house or school?

Explanation

Households in Western Australia use approximately 44% of their water outside the home. Therefore,

the garden is a great place where we can save some water. Having a water wise garden is

particularly important as we have a very dry climate compared to other parts of the world. Being

water wise isn’t just about the plants you choose. It involves having healthy soil (achieved through

the addition of mulches and wetting agents), hydro-zoning; grouping plants that have similar water

requirements together in the garden, only watering once on your allocated watering day, using a

watering can or trigger nozzle on your hose, and installing trickle irrigation to reduce evaporation.

Different plants have different requirements that include water, shade, and soil type. If these are

not provided your plant may not grow properly or even at all. Water wise and native plants grow

much more effectively than others in our harsh environment. It is also important to recognise that

some seedlings and plants grow well at particular times of the year when they are “in season”.

Trying to grow seedlings outside these times may be difficult or may not even happen at all!

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Real World Relevance

Using native plants in the garden, or observing those found in the bush and at nature parks use less

water compared to non-native varieties. They also encourage native fauna in to the area as they

provide food and shelter for these animals.

On average Western Australian households use 350 thousand litres of water per year. With 44% of this used on the garden, doing your bit to save water can reduce household consumption significantly.

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Activity 3.1 – Mini Water Cycle

Aim

To recognise the water cycle and discover why it is important to conserve liquid water in dry

environments.

Curriculum Links

Year 5 Chemical

Year 6 & 7 Earth and Space

Objectives

To have students use their understanding of the properties of water and with this knowledge

ask questions and make predictions about how the water cycle works and why it is

important. They will design and carry out an investigation to test the importance of

conserving liquid water in dry environments. Students will recognise that water use and

management relies on knowledge from different areas of science and involves the use of

technology to utilise that water in an effective way. Students will also consider issues relating

to the use and management of water in their community and beyond.

Duration

1.5 hours

Safety and Disposal

No specific safety measures are needed. All the liquid waste can be poured on the garden and

the solid waste recycled or thrown away.

Materials

8 plastic takeaway containers

Plastic jug

Plastic wrap

Elastic bands

8 Zip lock bags

Ice cube trays

Water

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Method

Pre-freeze water in ice cube trays the night before starting this activity

Start this activity with a discussion about water. Review with the students the properties of water.

They should know and understand the states of matter and the high heat capacity of water. Re-

iterate that water is the only naturally occurring molecule on this Earth that can be found in all three

states. Key questions are: Why is water important? What do we use water for? What do other living

things use water for?

Introduce the concept of the water cycle. Water moves through each of the phases, so does that

mean it’s never really lost? What does evaporation mean? Can the students provide an example

where they have seen evaporation occur? What does condensation mean? Can the students provide

an example of where condensation occurs in the environment? In this activity the students will be

building an apparatus to look at the how the water cycle works and recognise that the missing water

is not lost; it is simply cycling through each phase or state.

1. Divide the class into small groups. Give each group of students’ one container to share.

Allow the students to discuss in their group what they would like to test for. Students can

decide how much water they will put in their containers, and where they will leave it

(outside, at the window, in the dark). What type of environments might their choices be

replicating? – Dry, wet and/or humid?

2. Encourage the students to make a prediction, write it down for comparison later in the

experiment.

3. Fill the plastic containers with water. The amount of water used will depend on what

conditions the students are testing. As the experiment will be carried out over a short

period of time it is recommended that the maximum amount of water placed in the

container just covers the bottom.

4. Cover each container with plastic wrap and secure it in place with the elastic band. Do not

pull the plastic wrap tight.

5. Place an ice cube in the zip lock bag and seal it. Place the bag on top of the plastic wrap in

the centre of the container.

6. Gently push the ice down about 2.5cm so the plastic wrap slopes down towards the middle.

7. Place the containers near a window where it will be heated by the sunlight.

8. Observe the underside of the plastic wrap every 5-10 minutes for up to one hour, or until

the ice melts.

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9. The students should record their observations during the testing time and after the

experiment has been completed. What has happened? Can the students attempt to explain

why?

Extension Activity

Students should compare their results with other groups and see if their observed differences can be

explained scientifically. Which group(s) tested conditions similar to a Western Australian

environment? Encourage a class discussion on why we need to save water in Western Australia,

especially since we have just learned that water is never really lost, it simply travels through the

water cycle. How would pollution affect the water cycle and what are the implications of this?

Repeat the experiment again using different types of soil (try sand, potting soil, mulch etc) in the

bottom of the containers. Students should predict how the amount of condensation will differ with

different soils. Is there a way of replicating different environments (tropical for example)? What if

the heat source was altered, changed, or taken away all together? How would adding plants and

animals affect the water cycle?

Explanation

This is a mini model of Earth’s water cycle. In this experiment we have seen the water in the container changed from a liquid to gas and back again. As the container was in the sunlight the water inside heated up and changed into water vapour (gas) which rose up towards the ice, a process called evaporation. You can see evaporation when you put the kettle on to boil water; the steam coming out of the top is water that has been evaporated. When the water vapour reached the ice it was cooled. When gas is cooled it undergoes a process called condensation. Condensation occurs when a gas is transformed back in to a liquid. This process could be seen in this experiment when the small droplets of water appeared on the underside of the plastic wrap. Clouds are formed when water vapour in the air undergoes condensation. In a cloud when enough water has condensed the water droplets become too heavy fall back to earth as precipitation (or rain), and the cycle starts all over again. These steps are all part of the ‘Water Cycle’ which is good for us because the Earth has a limited amount of water. When it rains, water can be collected at the bottom of hills, often in oceans and lakes. This water is referred to as “runoff”. Transpiration, a process that happens in plants and trees (see the “Colouring Celery” activity) also provides some water as the vapour leaves the plants and moves upwards in to the atmosphere. Runoff and transpiration are also important parts of the water cycle. The water we used in this experiment has been around as long as Earth has!

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Real World Relevance

Neil de Grasse Tyson (astrophysicist and science communicator) once had this to say about water on earth:

“There are more molecules in a cup of water than there are cups of water in all the world’s oceans. This means that some molecules in every cup of water you drink, passed through the kidneys of Ghengis Khan, Napolean, Abe Lincoln or any historical person of your choosing.”

This simply means that all of the water that we drink and play in today is made up of the same water molecules that were around when the dinosaurs walked the earth. Over time water has been evaporated from the oceans and lakes moved in to the clouds where it has condensed and then precipitated back towards the Earth’s surface as rain. Some of this rain soaks into the soil which eventually runs into a lake, dam or ocean to start the process all over again. Other rain drops are collected by plants and animals (including humans) and drunk. This water ultimately makes it back into a lake, dam or ocean to start the process all over again. In Western Australia we often use dams to collect this freshwater.

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Activity 3.2 – Water Purification

Aim

To purify a sample of unclean water

Curriculum Links

Year 4, 6 and 7 Chemistry

Objectives

The students will use a variety of processes to purify a dirty water sample. Students will plan

and conduct their own experiment based on their understanding of filtration. They will use

different tools to carry out the experiment, recording and measuring their results. Students

should compare their results with other groups recognising different filtration mechanisms.

Duration

This activity has been designed to be carried out in at least two sessions. The duration of each

component of the activity is at the discretion of the presenter.

Safety and Disposal

Do not ingest water samples before or after it has been filtered through the self-made

filtration devices. They are not safe to drink. Water that has been filtered through the Life

Straw is safe to drink (although the straw may not alter the taste).

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Materials

Life Straw

Cup or glass (for drinking out of)

Sample of dirty water (optional)

8 soft drink bottles cut in half

Water

Large beaker

Paper towels

Gravel

Sand

Cotton wool balls

Oil

Food colouring

Pieces of paper

Styrofoam pieces

Method

Discuss with the students the importance of water, especially for drinking. Can we drink just any

water? Why does it need to be filtered? What does filtering do? Allow and encourage the students

to research about water quality for Australia compared to other countries (particularly developing

and third world). What have they found? Students should communicate their findings verbally and

may even design an information poster for the classroom.

Introduce this experiment as a way to discover how filtration works. Each student or group will get

the opportunity to design a filter and a sample of dirty water will be used to test its efficiency.

Filtering water is important for humans as dirty water can contain chemicals, waste, bacteria and

viruses that can make us very sick and even cause death. Some countries do not have access to clean

water. The Life Straw can now be used and filters water to an acceptable drinking standard.

Demonstrate how the Life Straw works using a dirty water sample of your own. Pour the sample in

to the blue catchment bucket. Once the sample has travelled through the filtering mechanism you

will be able to release the water using the pale blue handle. Collect the water in a glass to show the

students what it looks like. Now try drinking it! Don’t worry, it’s quite safe.

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Before you start:

It is recommended to introduce the concept of this activity up to a week in advance to carrying

out the experiment. This way, the students can collect different items from around the school,

classroom, or home to test as filtration devices during the experiment. It can then be run as a

competition.

You may like to encourage each student to bring their own bottles and do this experiment

individually.

Students should work together in small groups, or individually to research what would make a good

filter. They should then plan what materials they will need and how it will work before starting the

experiment. They can then use the following steps as a guide.

1. Place the top half of the soft drink bottle upside down inside the bottom half to create a

funnel. The top half will be the filter and the bottom half will hold the filtered water.

2. Mix the oil, food colouring, pieces of paper and Styrofoam balls in the large beaker, creating

the dirty water to be filtered.

3. Encourage the students to experiment with the materials and the order they are placed

inside the bottle. How will their design filter out the contaminants? What is the most

efficient order to place the materials? You may like to suggest different materials that will

filter most effectively. These types of materials will take out different sized particles as the

water travels through. It is best to remove the largest contaminants first. Examples might be

different sizes pebbles or sand, filter paper, sponges or cloth.

4. Pour the dirty water into the bottle and allow it to trickle through the filter. What does the

filtered water look like? How does this compare to the unfiltered water?

5. Pull apart the filter and separate each material. Can the students identify what each material

separated from the water?

Now that the students have tested their filters, allow them to view all of the different designs,

paying particular attention to materials used and water clarity. As a group discuss which of the

designs was the most effective and why.

Re-introduce the Life Straw. Discuss the ways in which it filters water through. Did anyone think to

do something similar? The Life Straw has a course filter in the blue catchment bucket and a fine

hollow fibre filter in the straw component. This removes fine particles as well as viruses and bacteria

from the water sample.

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Extension Activity

Now that the students have discovered how effective their filter was, can they improve on their

design? Clean the bottles and ask the students to repeat the experiment. They may even like to try

something similar at home.

Discuss with the students how they might apply what they found to building a water treatment plant

for a city. What contaminates might be in the water? How could you filter them out? What are some

methods you would use to check to make sure the water is safe to drink?

Explanation

In Australia, our water is filtered and disinfected so that it is safe to drink (unless otherwise marked).

These processes remove or kill harmful contaminates that would otherwise make the water unsafe

to drink. However, approximately 40% of the global population does not have access to clean

household piped water. Unsafe drinking water is a leading cause of diarrhoeal diseases that

particularly affect children and people who are already sick or malnourished. Water filters are the

most effective way to clean water and can significantly reduce the likelihood of diarrhoeal disease

and waterborne infections.

Treating water to remove contaminants began in the 19th century. We have since come a long way

and can now ensure our water is of the highest quality. The most widely applied water treatment

process is a combination of some or all of the following; coagulation, flocculation and sedimentation

followed by filtration. This has been used since the start of the 20th century.

Water in Australia is also disinfected to kill any pathogens that may still be present after the above

processes have been carried out. This reduces the risk of waterborne diseases. Disinfection can be

performed using chemicals such as chlorine or through ultra-violet (UV) radiation.

Key Terms

Sedimentation: the water is left to settle allowing particles to drop to bottom of the vessel.

Flocculation: the finer particles left suspended in the water sample after sedimentation are

treated with chemicals (or coagulants). These chemicals react with the unwanted particles to

form larger particles, known as floc. The weight of the larger particles will cause them to

settle to the bottom of the vessel rapidly. An example of a typical coagulant is Alum.

Coagulation and flocculation are able to remove fine particles from the water sample that

often attract bacteria and viruses. This process can remove up to 99.9% and 99% of bacteria

and viruses respectively.

Filtration: this process can remove even smaller particles still remaining in the water sample.

It is done so by passing the sample through a bed of fine particles, generally sand. Other

filters may use gravel or charcoal too. New synthetic materials are also being developed for

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filters, such as the Life Straw where the water is passed through a membrane. These

membranes contain pores, the smaller the pores (holes) the better the water is filtered.

Real World Relevance

885 million people do not have access to improved sources of water. Unclean water causes 4 billion

cases of diarrhoeal diseases each year. These diseases cause dehydration and can sometimes lead to

death. School students in countries that do not have clean water are often too sick to go to school.

Simple devices like the Life Straw can help prevent these illnesses through its filtration mechanism.

The Life Straw Family can filter up to 18, 000 litres of water which is enough to supply a family for 3

years. This device can filter out bacteria, virus, protozoan parasites and dirt.

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Activity 3.3 – How “Flow” Can You Go?

Aim

To compare flow rates of different shower heads and gain an understanding of how important

it is to conserve water.

Curriculum Links

Year 4 Chemical

Year 5 Biological

Year 6 & 7 Earth and Space

Objectives

To introduce water conservation and ways to minimize water usage.

Duration

20 minutes

Safety and Disposal

Be water wise and dispose of the water from the experiment in the garden.

Materials

Regular shower head

Water saving shower head

Stopwatch

Bucket

Tap and hose

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Method

This activity is best run in small groups and can be done simultaneously with another activity in

this section.

Discuss as a group why saving water is so important. Can the students provide simple examples of

where water can be saved around the home? One example is installing a water saving shower head

in the bathroom. Introduce the concept of the activity to the students. Allow them to make

predictions as to how long it will take for each of the shower heads to fill the buckets. What are

these predictions based on? How long do you spend in the shower? How much water do you think

you might use?

1. Attach one of the shower heads to the tap and run the water through it, catching it in the

bucket.

2. Fill the bucket with water for 30 seconds. Measure how much water is collected.

3. Repeat for the other shower head.

4. Multiply your answers by 2. This will tell you your flow rate, or how much water (in litres) is

passing through the shower head per minute. Record it as your answer in L/minute.

Discuss the results in groups and as a class. Which shower head is the water saving one? How do you

know this? What does this mean for saving water at home? What can each student do to ensure

they are saving water at home and at school?

Extension Activity

Have the students brainstorm about ways that they could conserve water at home. Some ideas

include turning off the tap when brushing your teeth and fixing or replacing leaky taps. Have them

record their daily activities that use water on the worksheet. See who uses the least amount of

water. What tasks use up the most water? How could they use less water?

Each student can calculate the number of litres of water they use on average during their shower.

They will need to multiply the flow rate calculated earlier by the number of minutes they spend in

the shower. What is the difference in amount of water consumed for the normal shower head

versus the water saving one?

What would make a good rain water collector? Where would be the best place to put it? What could

you use the water for? How would you get the water out of the collector? Challenge them to design

and make their own then wait until the next rainstorm and test them out. Alternately have them

create a rain collector at home.

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Explanation

Households use over 50% of their water in the home. Showers and baths account for 25% of all

water used in the average home. That is a lot of water, but also a great opportunity to save water.

The Water Corporation recommends limiting showers to 4 minutes or less and installing a water

saving shower head.

Water saving showerheads work in many different ways. Commonly they work to restrict water flow

with a simple plate inserted to prevent excess water from being pumped through. They also increase

the water pressure as a higher pressure in the shower will mean less water is consumed in total.

Other shower heads found on the market have timers and automatic on/off switches to try and

encourage users to just get wet, bathe without running water and then rinse off later.

You are able to tell whether your shower head is water wise or not by doing this simple experiment.

If the shower head fills a 10 litre bucket in less than 1 minute then it is considered waterwise.

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Activity 3.4 – Water, Water Everywhere and Not a Drop to Drink

Aim

To determine the amount of water available on this Earth for consumption.

Curriculum Links

Year 4 Chemical

Year 5 Biological

Year 6 & 7 Earth and Space

Objectives

To help the students visualize and understand the percentage of drinkable water on the earth.

Duration

20 minutes

Safety and Disposal

Do not drink the water used in this demonstration. Dispose of the water wisely.

Materials

Bucket

Water

5 beakers, various sizes

Food Colouring

Pasteur Pipette

World Map

Method

This is a teacher led demonstration to showcase the availability of Earth’s water supplies.

You may like to start this activity as a guessing game to see if the students can predict how much

water is available to drink proportionally when given an amount of water. Encourage the student to

discuss what water is used for, where we might find it and in how many different forms (states).

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Introduce the students to the concept of “proportions”. What does this mean and why do we use

them?

1. Fill up a 10L bucket with water. This represents all of the water on Earth. Ask a student

to remove how much water they think is fresh water. How accurate was their

prediction? Fresh water can be represented using 300ml of water from the bucket (3%

of the total water on Earth). Dye the water in this container.

2. Asking different students each time, repeat the above process to estimate how much of

our fresh water is frozen, underground, in the atmosphere, and finally surface water.

Use the water from the original 300ml for this to demonstrate how it is divided up. The

table below will help you.

Where does all the water go?

10 L All of the water on Earth 100% of the total water on Earth 300ml Fresh water 3% of the total water on Earth 204ml Ice caps and glaciers 68% of the available fresh water 90ml Ground water 30% of the available fresh water 4.5ml Atmosphere, ground ice water 1% of the available fresh water 1.5ml Fresh, liquid, surface water <1% of the available fresh water

Now that we have discovered that there isn’t much surface water can the students brainstorm what

we use all of this water for? Can they tell you what type of water is represented in the bucket we

used earlier? – Salty water.

This has been a visual representation of the water that we have to use on Earth. Can the students

explain why it is so important to save water? Discuss what happens to the fresh water once it

disappears down the drain. It travels in to the oceans and rivers and becomes salty water. Are there

ways to make use of other sources of water?

Extension Activity

This demonstration is designed to be directly followed by the “Build your own Aquifer” activity.

Explanation

Most of the water on our Earth is salty. Historically, human beings couldn’t use this water for

drinking and a lot of the other things we use water for. Instead, we had to use freshwater.

Unfortunately there is a very small percent of the total water on Earth that is fresh. Of this, an even

smaller amount is surface water. Therefore, it became very important to not only save the

freshwater we have, but also experiment with ways of using the salty water. We have now

developed what is called desalination plants. Desalination involves removing the salt from the water

in our oceans, making it appropriate for us to drink. At this stage, little water is used through

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desalination however continual advances in technology is making this process much faster and more

cost effective.

Real World Relevance

Even though 70% of the Earth’s surface is water, less than 1% of it is fresh water.

In Perth 46% of our drinking water comes from groundwater, 31% comes from surface water and

23% through desalination.

By mid-2013, the Southern Seawater Desalination Plant will contribute approximately 50% to our

water needs.

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Activity 3.5 – Build Your Own Aquifer

Aim

To demonstrate how water can be stored underground in an aquifer and how groundwater

can become contaminated.

Curriculum Links

Year 4, 6 and 7 Chemistry

Year 4 and 6 Biology

Year 6 and 7 Earth and Space

Objectives

Students will discover how we utilise groundwater as a water source and the dangers to us

and the world around us if it becomes contaminated.

Duration

1 hour

Safety and Disposal

Do not ingest the water used during this activity. Dispose of the water wisely. The cocoa used

in this activity is not appropriate to eat.

Materials

8 plastic containers

Plasticine

Sand

Aquarium gravel

Spray bottles

Felt

Cocoa

Food colouring

8 Pasteur Pipettes

Water

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Method

This activity is designed to follow the teacher demonstration “Water, water everywhere but not a

drop to drink”.

Students should now understand that we do not have an infinitely large supply of freshwater

available to us. Therefore, making use of water from other sources is very important. Introduce this

activity as a way of discovering how we can use our groundwater effectively. Can the students tell

you any problems with using groundwater as a water source? They may like to discuss droughts,

pollution, and engineering problems here.

Introduce the concept of an aquifer. Aquifers are underground layers of rock or sand that allow

water to be absorbed as well as lie on top. Groundwater can then be extracted from these using a

bore. Do the students know of any local aquifers?

Students may like to design their own aquifer or use the following steps as a guide.

1. Place a layer of sand along the bottom of the container a few centimetres deep. Slowly pour

water on to the sand to completely saturate it without having any water remaining on top.

You may need to shake the container to ensure the sand is saturated. Let the students

observe that the sand has absorbed the water. This is a model of what happens

underground

2. Flatten out the plasticine and place it over half of the sand to create a “confining layer”.

Make sure that the plasticine is attached to three of the walls in the container. Pour a little

more water on its surface. Let the students observe the water remaining on the top of the

plasticine. It is not being absorbed.

3. Place a layer of the rocks over the entire surface inside the container. Slope the rocks on one

side to create a hill and valley. Pour more water in to the valley of the aquifer until it is level

with the hill. Let the students observe the small lake (surface water) that has formed as the

sand can no longer absorb the water. This is an example of ground and surface water

supplies. We can use both these sources for drinking water.

INSERT DIAGRAM

Discuss as a group the advantages and disadvantages of using an aquifer to store water and as a way

of collecting water. In different environments (hot, dry, cool, droughts) would an aquifer work

differently? Why do we have to wait before the water can be collected? Encourage the class to start

thinking about the effects of pollution on water supply with their aquifer.

4. Place a small piece of felt on top of the hill. You may have to use some plasticine to secure it

down.

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5. Sprinkle some cocoa on top of the hill. This is representative of pollutants such as lawn

fertilisers. What else could it represent?

6. Using a pipette, add a few drops of food colouring on the rocky hill, as close to the edge of

the container as possible. This represents pollutants like fertilisers, rubbish, and car oils that

people often dispose of in lakes or dams. Can you think of other examples? Let the students

observe the colouring moving through the rocks, surface water supplies and sand. This is an

example of how pollution can contaminate groundwater over time.

7. Using the spray bottle, make it “rain” on top of the hill and over the aquifer. What is

happening to the pollution on the hill (cocoa)? What does this mean for our water supply?

8. Have a good look at the aquifer that was just made, paying particular attention to the

pollution. Compare it to the original. How it is different? What does this mean for our water

supply?

Discuss what this activity means for Australia’s ground water supply. How can the students

themselves encourage changes to minimise pollution in our waterways? Can the students

communicate what happens to the groundwater once it is collected in a bore before we can

drink it? They can use their knowledge from the Water Purification activity to answer this.

Extension Activity

Apart from gathering surface and groundwater, Perth also uses a desalination process as a source

for more drinking water. After researching how desalination works, can the students figure out a

way of gathering fresh water from a salty sample?

Explanation

Aquifers can be man-made, or formed naturally and need a semi-permeable surface for the water to

be firstly absorbed into before the excess can be stored on the top as a lake. In this activity, this

surface was the sand. When it rains, water travels directly in to the lake or as runoff from the hills

and is captured in the valley. This is known as infiltration. Once the water has had enough time to be

absorbed by the bottom layer of the aquifer, it is able to be extracted by the well. The water is

pumped, used for drinking water after undergoing a filtration and disinfection process.

Unfortunately, pollutants can seep in to the water from two different sources. Sometimes,

pollutants enter with the runoff from the grounds above the aquifer. These pollutants are often

different fertilisers. Pollution can also be directly added when people dispose of dangerous wastes in

to dams and lakes inappropriately. All of the pollutants ruin this water source for us and can make it

dangerous to drink.

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Real World Relevance

In Perth, 46% of our drinking water comes from groundwater. It is therefore very important to keep

our waterways clean so we can continue to use this as a reliable water source.

There are many different ways of catching and recycling water that you can even do in the back

yard. Rainwater tanks can be used to collect rain and store it just like aquifers do. This water may

not be able to be used for drinking (unless it gets treated) but you can use it to water your plants

and garden.

You can also recycle your grey water. Grey water is used water from showers, washing machines and

dishwashers for example. Through installing a treatment system outside the home the water that

you use inside can then be used on the garden.