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Assessment for Learning Chemistry: what happens when a substance changes state?

Description

Assessment for Learning is an effective way of actively involving students in their learning. Each session plan comes with suggestions about how to organise activities and worksheets that may be used with students.

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A series of resources linked through concept or context which can be used in whole or in part during teaching or learning.

ADDITIONAL INFORMATION

If you teach primary science, click the headings below to find out how to use this resource:

Skill development

Children will develop their working scientifically skills by:

  • Drawing conclusions and raising further questions that could be investigated, based on their data and observations.
  • Using appropriate scientific language and ideas to explain, evaluate and communicate their methods and findings.

Learning outcomes

Children will:

  • Compare and group materials together according to whether they are solids, liquids or gases.
  • Observe that some materials change state when they are heated or cooled.

Concepts supported

Children will learn:

  • What is meant by the terms boiling, melting, solidifying and freezing, and that cold temperatures are not a requirement for freezing.
  • What does and doesn’t happen when substances change state, including:
    • That molecules do not break up and reform when a substance boils and/or cools.
    • That particles stay the same size and shape during changes of state.
  • That particles are always moving when they are at any temperature other than absolute zero.

Suggested activity use

The experiments in the activity can be used as a demonstration to stimulate discussion and questions about what is actually happening when substances change state. Alternatively, the mini experiments could be adapted and the children could carry these out in small groups, noting down their observations and ideas.

Practical considerations

Access to and use of Bunsen burners in primary schools can be difficult, so viable alternatives may need to be sourced.

Note that primary children may not need to go into as much detail as looking at molecular models of water.