Science Double Award Co-Ordinated (0654) iGCSE 2026 Chemistry 1 (The Particulate Nature Of Matter, Air And Water)

What are the distinguishing properties of solids?

Fixed shape and volume, particles are closely packed and vibrate in fixed positions.

What are the distinguishing properties of liquids?

Fixed volume but no fixed shape, particles are close together but can move past each other.

What are the distinguishing properties of gases?

No fixed shape or volume, particles are far apart and move freely in all directions.

What is melting?

The change from solid to liquid

What is boiling?

The change from liquid to gas

What is evaporation?

The change from liquid to gas at the surface of a liquid, occurring at any temperature.

What is freezing?

The change from liquid to solid

What is condensation?

The change from gas to liquid

How are particles arranged in a solid?

regular arrangement, touching

How are particles arranged in a liquid?

Touching and random arrangment, particles slide past each other.

How are particles arranged in a gas?

Far apart, moving randomly and freely in all directions.

How does increasing temperature affect the volume of a gas?

Volume increases because particles move faster

What causes pressure

Gas particles colliding with the surface of the container

How does increasing pressure affect the volume of a gas?

Volume decreases

According to kinetic particle theory, why does increasing temperature increase gas volume?

Particles gain kinetic energy, move faster, and collide with more force, pushing outward.

According to kinetic particle theory, why does increasing pressure decrease gas volume?

More frequent collisions force particles closer together, reducing space between them.

How does kinetic particle theory explain melting?

Particles gain energy, vibrate faster, and break free from their fixed positions.

How does kinetic particle theory explain boiling?

Particles gain enough energy to completely overcome intermolecular forces

How does kinetic particle theory explain freezing?

Particles lose energy, move slower, and settle into a fixed, regular structure.

What does a heating curve show?

How temperature changes over time as a substance is heated, showing no at melting and boiling points where energy is used to break bonds.

What does a cooling curve show?

How temperature decreases over time as a substance cools, with plateaus at freezing and condensation points where energy is released.