Year 8 Earth and Chemistry Revision

Which of these is a chemical reaction?

• boiling

• burning

• condensing

• melting

Which of these describes a physical change?

• A liquid catches fire

• A liquid cools down and changes into a solid.

• A solid changes colour and releases a gas when heated.

• A solid fizzes when added to an acid.

Gas pressure is caused by gas particles …

• attracting each other.

• hitting each other.

• hitting the walls of the container

• moving around.

The pressure of a gas increases as the temperature increases because …

• there are more particles in the container.

• the particles are further apart.

• the particles get bigger.

• the particles move faster.

The type of change when a metal reacts with oxygen is …

• distillation.

• neutralisation.

• oxidation.

• thermal decomposition.

Which of these shows the essential conditions needed for iron to rust?

• air only

• air and water only

• air, salt and water only

• water only

A hydrocarbon contains the elements hydrogen and carbon only. Which of these formulae represents a hydrocarbon?

• C3H8

• C6H12O6

• CO2

• NaHCO3 3 Which of these

Which of these statements are true?
a. A mixture is made up of different substances that are chemically joined together.
b. You cannot change the amounts of substances in a mixture.
c. A pure substance has no other substance mixed with it.

• a, b and c
• only b and c
• only a
• only c

Weathering...

• breaks rock into smaller pieces AND moves them away from the original rock.
• involves the weight of sediment above making sediments below stick together.
• breaks up all types of rock into smaller pieces called sediments. There are 3 types of weathering, Physical, Chemical and Biological.
• is the settling of sediments.

Igneous rocks are formed when liquid rock cools and freezes. Which of the following is true?

• Above ground, liquid rock cools and freezes quickly. The particles can make large crystals.
• Above ground, liquid rock cools and freezes slowly. The particles can make small crystals.
• Underground, magma cools and freezes quickly. The particles make small crystals.
• Underground, magma cools and freezes slowly. The particles can make large crystals.