Materials and Their Properties

Lesson Objectives

All - know what property meansstate some common

properties of metals and non metals

Most - relate properties of metals and non metals to their uses

Some - choose a material for a certain use and explain why it is suitable

List all the materials that you think are in a mobile phone.

Why are they used?

Properties of materials are used to describe materials.

There are 2 types:

•Physical properties

•Chemical properties

Properties of metals are used to describe metals.

Physical properties can be observed about a substance that doesn’t involve a chemical change.Examples?

Properties of metals are used to describe metals.

Chemical properties involve CHEMICAL CHANGE.e.g. Burning in oxygen, reacting with acids

CopperWhy is copper used to make

pans?

GoldWhy is gold used to make

jewellery?

Aluminium2 reasons why aluminium is used

for overhead cables?

Titanium2 reasons why titanium is used for hip replacements?

Testing materials – Physical Properties

• Physical properties include:• Thermal conductivity- how well heat

travels through it.• Electrical conductivity - how easily

electricity travels through it.• Melting and boiling points• Solubility in water - how much dissolves in

100g of water at a fixed temperature• Viscosity - how treacly a liquid is.• Density – how heavy a fixed volume of the

material is.

Testing Thermal Conductivity

copper

Results

Substance How long did it take for the cobalt chloride paper to turn blue?

Put the substances in order, from best heat conductor to worst

brass    

iron    

glass    

copper    

Testing the Properties of Metals & Non-Metals

Test 2: Electrical Conductivity

1. Set up a circuit like above.2. Connect up the iron nail as shown in the diagram. Does the bulb light up?3. Write your result in the table below.4. Now try the experiment again with the other things.

Substance Bulb on or off? Conductor or insulator?

iron

plastic

glass

wood

copper

aluminium

Test 2: Electrical Conductivity

Finding density

1. Weigh the block on a balance.

2. Record the mass in g.3. Carefully lower the block

into the displacement can as shown in the diagram.

4. Collect the water and measure the volume in cm3

5. Density = mass volume6. Use the expression to work out the density and record

it in the table.

Density - Results

Object Mass (g) Volume(cm3) Density (mass÷vol)

Stone

Aluminium block

Wax

Plastic block

ConclusionWater has a density of 1g/cm3

Anything with a density greater than 1 _____.Anything with a density less than 1 _______

Lesson Objectives

All - state some common properties of materials (PASS P2)

Most - relate properties of materials to their uses (MERIT M2)

Some - choose a material for a certain use and explain why it is suitable (DISTINCTION D1)

How Physical Properties Determine Uses of Materials

• Assignment 1.2• ALL must complete 3 practical

investigations SAFELY and record results.

• MOST should complete and record all 4 (pass)

• SOME may continue research into the properties and structure of materials.(merit/distinction)

Testing Other Physical Properties

• 1. Solubility of solids.• Substances are INSOLUBLE if the forces

holding the a______ together are too s______ to be broken by water.

• 2. Viscosity of liquids• Liquids are VISCOUS if they are made of

l_____ c_____ molecules which can t_____ together.

• 3. Melting point• Substances have HIGH melting points if the

forces holding a_____ together are s_____.

Testing Other Physical Properties

• 1. Solubility of solids.• Substances are INSOLUBLE if the forces

holding the atoms together are too strong to be broken by water.

• 2. Viscosity of liquids• Liquids are VISCOUS if they are made of long

chain molecules which can tangle together.• 3. Melting point• Substances have HIGH melting points if the

forces holding atoms together are strong.

G_____ c_____ of h____

G____ c_____ of e______

M_____

D______

S____

H___ m____ and b_____ p______

S_____

H____ D______

Good conductors of

heat

Good conductors of electricity

malleable

ductile

shiny

High melting and boiling points

strong

High density

P____ c________ of

h____

P____ c______ of e________

Usually d____

L__ m_____ and b_____ p_____ Not s_____

Properties of Non Metals

Poor conductors of

heat

Poor conductors of electricity

Usually dull

Low melting and boiling points Not strong

Properties of Non Metals

Lesson Objectives

All - state some common properties of materials (PASS P2)

Most - relate properties of materials to their uses (MERIT M2)

Some - choose a material for a certain use and explain why it is suitable (DISTINCTION D1)

copper

COPPERStructure:

ALUMINIUM

Structure:

MetalsC____ packed l______ of atoms.Free to move negative e_______ flow through the structure holding it t______.

Even when b___ or hit the structure stays strongly bonded together. The atoms just s____over each other.High d_____ because atoms close p_______.M______ electrons carry an electric c____ or heat e_______through the structure.

MetalsClose packed layers of atoms.Free to move negative electrons flow through the structure holding it together.

Even when bent or hit the structure stays strongly bonded together. The atoms just slideover each other.High density because atoms close packed.Moving electrons carry an electric current or heat energy through the structure.

GLASS

Structure:

GlassA n__ m____ c_________.R_______ structure of molecules.No c______ so t__________.W________ bonded so brittle.No f_____ electrons so n___ conductor of h____ and e_______.Low d_______ because of open, r_______ structure.

GlassA non metal compound.Random structure of molecules.No crystals so transparent.Weakly bonded so brittle.No free electrons so non conductor of heat and electricity.Low density because of open, random structure.

POLYTHENE

Structure:

Polythene

A n__ m____compound.L_____ chains of carbon and hydrogen atoms s_____ bonded together but very w____ forces between chains. R______ chains.

N_ crystals.N_ free e______ so a non c______ of h_____ and e__________.

Flexible because the chains can s____ over one another.L__ density because of r_____ chains.

Polythene

A non metal compound.Long chains of carbon and hydrogen atoms strongly bonded together but very weak forces between chains. Random chains.

No crystals.No free electrons so a non conductor of heat and electricity.

Flexible because the chains can slide over one another.Low density because of random chains.