Author: Amanda McGarrigle

Science
States of matter —evaporation and condensation

Background Information
In this unit, children will learn about the different states of matter and the effects these have on our everyday life. They will be focusing on evaporation and condensation. Evapouration is the process of turning something from a liquid to a vapour (gas). Condensation is the change of a state of matter from a gas into a liquid. These processes are key for everyday life, and are an essential part of the water cycle.

Key scientist
Alfred Barnhard Nobel (1833-1896)
Royal Society of Chemistry

In this unit the children will…
Work scientifically to find results to different experiments.
Identify the part played by evaporation and condensation in the water cycle and associate the rate of evaporation with temperature.
Observe and record evaporation over a period of time.
Draw simple conclusions and use some scientific language.

By the end of this unit….
All children can:
Define evaporation.
Define condensation.
Show some examples of evaporation.
Show some examples of condensation.
Identify some aspects of the water cycle.
Participate in scientific experiments.
Write up results from an experiment.
Most children will:
Define and explain the process of evaporation.
Define and explain the process of condensation.
Be able to explain the water cycle.
Write up and explain the results of an experiment.
Some children will:
Explain the importance of evaporation and condensation in the water cycle.
Use scientific evidence to support their findings.

Key Vocabulary
Melting – When heat is applied to a solid the particles vibrate more, reducing the forces holding them together. This causes them to move apart, breaking the solid structure and becoming a liquid.
Evaporation – When heat is applied to a liquid the particles move around even faster, breaking away from each other and forming a gas or vapour.
When this happens to all the particles it is called boiling
Condensation – When a gas has heat removed from it the particles in the vapour slow down, come together and loosely bond, returning to the liquid state.
Steam - Steam is the name given to the gaseous state of water at or above 100 degrees Celsius and is not visible.
Water vapour - Water vapour is the gaseous state of water below 1oo degrees Celsius and is visible as tiny water droplets.