7GH Test

Clevedon Community School

Science Department

Test 7GH Particles and Atoms

40 marks

Answer all the questions on the lined paper provided

Â

7G Â 1

Are these things solids, liquids or gases? Write your answer below each one. a

b

c

brick

sea water

steam

d

e

f

wood

metal

milk

[3 marks]

2

Tick the columns in the table to show which are properties of solids, liquids and gases

Property

Solid

Liquid

Gas

Fixed shape Fixed volume Easy to squash Flows easily

[3 marks] 3

Draw diagrams in the boxes to show how the particles are arranged according to the particle theory. Use O to represent one particle.

Solid

Liquid

Gas

[3 marks]

4

Petrol is a liquid. When you fill up the petrol tank of your car, petrol flows through a pipe into the tank.

a

Why could you not fill up the tank in this way if a car used a solid fuel like coal?

[1 mark]

b It is possible to run an engine using a gas such as hydrogen as a fuel.

Explain one problem that you would have if you wanted to fill up the fuel tank with a gas.

[1 mark] 5

a

How do the air particles inside a car tyre cause pressure on the tyre?

[1 mark] b A driver pumps up the tyres of her car. What happens to the pressure inside the tyres?

[1 mark]

6

You can smell dinner cooking while you are watching TV. The smell has spread by diffusion. a

Use particle theory to explain why diffusion happens.

[1 mark]

b Use particle theory to explain why diffusion doesn’t happen in solids.

[1 mark] c

Does diffusion happen faster in a liquid or a gas? Explain your answer.

[1 mark]

7

In 1827, Robert Brown noted the random movements of pollen grains in water under a microscopic. He thought that the movements were due to the pollen grains being alive.

So, he repeated the experiment with 100 year old ‘dead’ pollen grains. He noted the same movements. It was similar with other small specks of matter such as soot and smoke.

The movements became known as Brownian motion. a

What was Robert Brown’s first hypothesis about the movements of the pollen grains?

[1 mark]

b How did he test his hypothesis?

[1 mark] c

Explain Brownian motion by using the particle theory of matter.

[2 marks]

7H Â 8

a

Name a type of substance that a saucepan would be made from.

[1 mark] b

Glass is used to make windows. Why is this material used?

[1 mark] 9

The table below has split some elements into three different groups.

Group 1

. copper sulfur aluminium

Group 2 Liquids

Group 3 Gases

mercury bromine

oxygen nitrogen

a Suggest a name for the first group of elements.

[1 mark] b Give the name of another element that would fit into group 3.

[1 mark] c

Copper and aluminium are both used to make electrical cables. What property makes them suitable for this use?

[1 mark]

10 Use the substances listed in the box below to answer these questions. aluminium a

carbon dioxide

iron

nitrogen

oxygen

silver

Which substances are metals?

[1 mark] b

Describe two properties of non-metals.

[1 mark] c

Which of the substances are the two main gases in air?

[1 mark] Elements can be represented by symbols. Complete the table below by adding the missing names and symbols.

Element

Symbol

hydrogen copper Mg Cl

[2 marks]

11 Glass is made from a number of different substances. The properties of glass depend on the amounts of each substance in the mixture.

Substance used for glass silicon dioxide

70

sodium sulfate

15

calcium oxide

10

other

a

% content

5

Complete the bar chart above to show all the substances in glass.

[1 mark]

b What other type of chart or diagram could you use to show this data?

[1 mark] c

What element do the top three compounds in the table have in common?

[1 mark] d Calcium oxide is made by heating calcium carbonate strongly for some time. Write a word equation for this reaction.

[2 marks] 12 Over 2000 years ago the Greek philosopher Plato put forward the idea that everything was made up of the four elements: air, fire, earth and water.

Another Greek philosopher, Aristotle, believed that an element was something that couldn’t be broken down into anything simpler.

Scientists have now found out much more about matter, and we now have different ideas on elements. a

Which one of Plato’s four elements was not a substance?

[1 mark] b Give a modern description of an element. Use the word ‘atom’ in your answer.

[1 mark]

13 Some of the main properties of metals are listed below.

•

strong

•

high melting points

•

shiny when polished

•

flexible

•

good conductors of electricity.

a

What does ‘flexible’ mean?

[1 mark] b State the name of a metal and one of its uses. Explain why it has this use by referring to one of the properties in the list above.

[2 marks]