Materials and Their Properties

Lesson Objectives All - know what property means state 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

Why is copper used to make pans?

Why is gold used to make jewellery?

2 reasons why aluminium is used for overhead cables?

Titanium 2 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.

Conductor or insulator? Test 2: Electrical Conductivity Substance Bulb on or off? Conductor or insulator? iron plastic glass wood copper aluminium

Finding density Weigh the block on a balance. Record the mass in g. Carefully lower the block into the displacement can as shown in the diagram. Collect the water and measure the volume in cm3 Density = mass volume 6. Use the expression to work out the density and record it in the table.

Density - Results Conclusion Water has a density of 1g/cm3 Object Mass (g) Volume(cm3) Density (mass÷vol) Stone Aluminium block Wax Plastic block Conclusion Water 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____ M_____ S____ H____ D______ G____ c_____ of e______ H___ m____ and b_____ p______ D______ S_____

Good conductors of heat malleable shiny High density Good conductors of electricity High melting and boiling points ductile strong

Properties of Non Metals P____ c________ of h____ Usually d____ Properties of Non Metals L__ m_____ and b_____ p_____ P____ c______ of e________ Not s_____

Properties of Non Metals Poor conductors of heat Usually dull Properties of Non Metals Low melting and boiling points Poor conductors of electricity Not strong

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

COPPER Structure:

ALUMINIUM Structure:

Metals C____ 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.

Metals Close 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 slide over each other. High density because atoms close packed. Moving electrons carry an electric current or heat energy through the structure.

GLASS Structure:

Glass A 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.

Glass A 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.