2/22/12

2/23/12 A/B DayLEQ: How does the polarity of water influence its physical properties?

1. What is buoyancy?2. What is surface tension?3. What is more dense—warm water or cold water?4. Why do we call water the universal solvent?5. Copy and complete: Water’s [high/low] specific heat means that it requires a [high/low] amount of heat for water to get hot!

Track your progress: Unit 2 Quiz D-1 = 96 -9 = 64 -17 = 32-2 = 92 -10 = 60 -18 = 28-3 = 88 -11 = 56 -19 = 24-4 = 84 -12 = 52 -20 = 20-5 = 80 -13 = 48 -21 = 16-6 = 76 -14 = 44 -22 = 12-7 = 72 -15 = 40 -23 = 8-8 = 68 -16 = 36 -24 = 4

Today’s LEQ: How does the polarity of water influence its physical properties?

By the end of today, you should be able to…

1. Describe the polarity of water.2. Explain why polarity creates cohesion

and adhesion of water

Focus Vocabulary

109. Polarity110. Cohesion111. Adhesion

CONTEXT CLUES:“Those two twins are polar opposites. They are

nothing alike.”

“The cowboys are such a cohesive team. They practice together, play together, and even eat all of their meals together!”

“The stickers that you put on your car have two sides—one side has a design on it and the other side is the adhesive side.”

Stop and Jot: Write your own definition of

Polar/Polarity

Cohesive/Cohesion

Adhesive/Adhesion

Draw this in your notes:Polarity:

Cohesion: Adhesion:

Draw this in your notes:Polarity: uneven charges in a water molecule; causes water to be sticky!

Cohesion: Adhesion:

Draw this in your notes:

Discovery Education Video:

Water’s molecular structure (How Stuff Works)

Water sticks to itself.

Water sticks to other stuff.

Draw this in your notes:Polarity: uneven charges in a water molecule; causes water to form bonds!

Cohesion: the tendency for water molecules to stick to other water molecules

Ex. Water drops stick together

Adhesion:

Cohesion Demo:

Can you get water to stick to itself?

Make a C with your fingers

Surface Tension—this happens because of COHESION!

Draw this in your notes:Polarity: uneven charges in a water molecule; causes water to form bonds!

Cohesion: the tendency for water molecules to stick to other water molecules

Ex. Water drops stick together

Adhesion: the tendency of water to stick to other substances

Ex. Water sticks to other things

Adhesion Demo:

Can you get water to stick to other stuff?

Make a C with your fingers

Adhesion—water sticks to the side of a straw

Adhesion

Other stuff!Water

WaterWater

Cohesion, Adhesion,

or Polarity?

Water sticks to a spider web

Water sticks together over the edge of a glass

Water has uneven charges

Water stays together on saran wrap

Water sticks together in drops

Water sticks to blood cells

Water creates bonds

Water sticks to a windshield

Water sticks to a leaf

Water has a positive and negative end!

Water ripples do not break the surface

Quiz-Quiz-Trade

WATER

Use your notes and your new knowledge to add on to your water bubble map!

Physical Properties

Polarity

Summarizer:1. What is polarity?2. What is the difference between cohesion

and adhesion?3. Water sticking to the side of a glass—is

this an example of cohesion or adhesion?

4. Water sticking to another drop of water—is this an example of cohesion or adhesion?