A plateau is a section of a graph that does not change value (stays at the same level for a period of time).

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

Freezing is the process of a substance changing from a liquid state to a solid state.

Measured using a thermometer (commonly in °C). Temperature is an indirect measure of the energy of the particles in a substance.

Cooling curve: practical

Science

In the Energy changes in reactions unit, pupils will build on this knowledge to learn more about exothermic and endothermic reactions, as well as learn about bond energies and reaction profiles.

In the Understanding chemical reactions unit, pupils learnt about how atoms move around to form new substances in chemical reactions and about some common types of chemical reactions.

Fuels and energetics

Physical activity and equipment requiring safe use

A constant temperature during a state change.

On a heating curve, what does a plateau indicate?

The point on a cooling curve where a liquid starts to solidify is called the {{}} point.

Energy is absorbed from the surroundings.

Energy is released into the surroundings.

Energy remains constant in the substance.

How does energy transfer during the cooling of a substance?

Which state changes are shown in this heating curve?

At what temperature (℃) does this substance begin to melt? (give only the number, not the unit) 

Because the energy is used to overcome forces of attraction.

Because the heating process stops temporarily.

Because the temperature measurement is incorrect (an error in recording).

Why does a substance's temperature not change during a phase transition, despite continued heating?

Which of the following is the most appropriate way to show the change in temperature over time?

The term used to describe the energy transfer from an object to its surroundings as it cools is...

True or false? In the gas state, particles have enough energy to move freely and are not held in fixed positions. 

They move further apart and move more quickly.

What happens to the particles of a substance when it is heated and reaches its boiling point?

The temperature at which a substance changes from solid to liquid is known as its...

particles have the strongest forces of attraction

particles have some (weakened) forces of attraction

particles have fully overcome forces of attraction

Match the state of matter to the description about forces of attraction.

Content guidance

Risk assessment required - equipment

Adult supervision required

Starter Quiz