PSLE Science Chemistry Topics

Question 1

Which of the following is an example of a chemical change?

Accepted Answer

Wood burning to produce ash and smoke

Answer

Ice melting into water

Answer

Salt dissolving in water

Answer

Glass breaking into small pieces

Question 2

What term describes the process when water vapour cools and turns back into liquid water?

Accepted Answer

Condensation

Answer

Evaporation

Answer

Sublimation

Answer

Melting

Question 3

Which state of matter has both a definite shape and a definite volume?

Accepted Answer

Solid

Answer

Gas

Answer

Liquid

Answer

Mixture

Question 4

Which of the following is NOT a physical change?

Accepted Answer

Iron rusting when exposed to water

Answer

Cutting paper into pieces

Answer

Dissolving sugar in water

Answer

Ice melting into liquid water

Question 5

When a solid changes directly into a gas without passing through the liquid state, this process is called:

Accepted Answer

Sublimation

Answer

Evaporation

Answer

Condensation

Answer

Freezing

Question 6

Which statement best describes particles in a liquid?

Accepted Answer

Particles are close together but can flow and move past each other

Answer

Particles are far apart and move freely in all directions

Answer

Particles are tightly packed and vibrate in fixed positions

Answer

Particles have no movement at all

Question 7

Heating water in a pot until it boils and produces steam is an example of:

Accepted Answer

A physical change, because the water molecules are unchanged

Answer

A chemical change, because a new substance is formed

Answer

A chemical change, because heat is involved

Answer

A physical change, because colour changes