Heating and Cooling Materials/Lesson

Pupil age: Year 2
mode of teaching: small groups of 6
location: classroom or cooking area
duration: 45 minutes

Rationale

In this inquiry-based lesson plan, students devise a ‘fair way’ to compare (mostly) physical changes in materials such as cheese and chocolate. They ask and answer questions about how to heat the materials and about using materials of the same size and shape. They also predict how substances may change and observe what actually happens.

The purpose of the lesson is to both support year 2 work on changing materials and to develop students’ ideas about ‘fair tests’. The activity thus offers an opportunity to assess how well students plan a test and how well they observe change.

Coping with challenges

• As a class activity, pupils may benefit from a template (writing frame) to plan; predict and record observations.
• To manage the assessment activity, the teacher may work with a small group while the remainder of the class perform other work
• Learning objectives or outcomes (National curriculum reference)
• Say how some everyday materials change when they are heated or cooled (Sc 3 2b)
• Observe heating or cooling to try to answer questions about them (Sc1 1).
• Use what they already know to answer questions (Sc1 2b)
• Recognise when a test or comparison is unfair (Sc1 2d)

Resources:

An oven and a freezer. Everyday materials such as chocolate, wood, bread, different cheeses, jelly sweets; marshmallow; ice, water. Heat resistant pots or containers, a tray, a knife and a spoon.

Lesson – what the teacher does

Explain to the children that we are continuing work on materials and today we will look at how materials ‘change’.

Start for example with what happens when they keep chocolate in a pocket. Or tell a story of a day when you were really looking forward to eating a chocolate bar and you left it in a hot car. (You cried and so on). Ask the children to think of, write or draw other examples where they have seen stuff change in everyday life. For example, when butter is left on the worktop; ice cream is left in a dish; or cheese is grilled on toast. Get pupils to describe how the stuff appeared when it changed. Ahead of the lesson you might want to make a list of words that pupils will find useful.

Continue talking about the everyday materials that have been used through this term. Recap on each material and what children know about it from previous activities. But now ask,

• Can we change the shape or texture of these materials by making them hot?
• How could we make them hot and see what happens?
• Where could we put them? Encourage the children to suggest ways of heating them. Discuss the safety aspects of using a heat source.

Work out how long each material will be on/under the heat source for a fair test to be planned. Get the children to predict what will happen to the material under the heat.

Place under heat and see what happens. When all have been heated, discuss the changes taking place – did they melt, go hard or soft? Could we say that heating changes the texture and shape of materials? Use the same format but concentrate on cooling everyday materials.

Assessment

Observe the children at the planning stage to see if they understand the idea of planning a fair test. After the investigation, listen to the children to hear whether they understand the idea that heating and cooling affect the shape and texture of materials.

Lesson – what the pupils do

Recap what the children know about the materials used for the investigation.

• Produce ideas of how we could change the materials’ shape or texture.
• Put forward ideas on how to heat the material. With help, children suggest ideas for the fair test.
• Predict what will happen and observe to see if they were right. Get together to discuss what happened and whether the things seen were what was expected.
• Answer the questions: how does heating (cooling) change materials?

Vocabulary for describing change

Science has its own words doesn’t it? List here the words that you think would equip your pupils with the language to describe change. Examples:

• it melted
• it turned liquid
• it softened

A science inquiry template to adapt

• The title of our investigation is
• We are trying to find out if ...
• What I think will happen is ...
• We think this will happen because ...
• We will need the following to do this investigation ...
• What we will do is ...
• What we will measure or look for is ...
• In our investigation, we will change...
• In our investigation, we will keep the
• following things the same ...
• To be safe we will make sure that ...
• I have learnt that ...