Substances in the liquid state will take the shape of their container.

Particles in a substance in a solid state are in a fixed position and can only vibrate.

The melting point of a substance is the temperature at which it changes from a solid state to a liquid state.

The freezing point is the temperature at which a substance changes from a liquid state to a solid state.

Melting: melting points and freezing points

Science

Solid and liquid states

Melting: particle model

Bunsen burners

Particle model of substances in the gas state

Boiling and condensing

Changes of state: energy and evaporation

In the Solutions unit, pupils will build on their understanding of the states of matter to learn about mixtures, solutions, and dissolving in terms of the particle model.

In Y4 of primary science, pupils learnt about ‘solids, liquids and gases’ and changes of state.

This unit covers the properties of solids, liquids, and gases using the particle model, including gas pressure. It explains changes of state in terms of the particle model while developing skills in using appropriate techniques, apparatus, and materials in lab work.

Solid, liquid, gas states and changes of state

particles fill the shape of the container

particles are in a fixed position and can only vibrate

temperature of a substance changing from a solid to liquid

temperature of a substance changing from a liquid to solid

At what point is a substance in its solid state?

Arrange the following phases in the order they occur when a substance is cooled:

The melting point and freezing point of a substance are {{}}.

If a substance has a melting point of 50°C, at what temperature will it freeze?

The substance must be entirely in the solid state.

The substance must be entirely in the liquid state.

The substance could be in the solid or liquid state, or both simultaneously.

A substance has a melting/freezing point of 25°C. If a sample of this substance is in a container at 25°C, which of the following statements is most accurate?

In which state of matter are particles in a fixed position and can only vibrate?

Which state of matter takes the shape of its container?

What is the temperature at which water freezes? {{}} ℃ (enter only a number)

Arrange the following transitions in the order they would occur when heating a substance:

The forces of attraction between particles are stronger

What is the primary reason that a substance in the solid state does not flow like a substance in the liquid state?

Melting: melting points and freezing points

Lesson outcome