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 20 October 2014

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Solids and liquids - lesson plan

Objectives

To investigate melting and cooling in a range of materials.

Sc3, 2b, 2c, 2d.

Teaching activities

Introduction

1. Watch Learning Zone Broadband Class Clips - Solids and liquids.
2. Ask how many solids, liquids and gases the children saw. Can they name any?
3. Arrange the class like solid particles (bunched closely together), then like liquid particles (a bit more energy and a little further apart) and then like gas particles (loads of energy, spaced far apart).
4. Ask the children to explain the properties of solids and liquids. Determine the key facts, such as solids keep their shape whereas liquids flow to fill containers.
5. Ask if a material always stays as a solid or a liquid. How can it be changed?
6. Ask for examples of things that change their state, such as ice-cream or snow melting. Show pictures of water, ice and clouds.
7. Explain that water freezes at 0°C. This is called the freezing point of water. It is also the melting point of ice.

Activity

1. Explain to the children that they are going to investigate the melting and freezing of a range of materials in a virtual experiment.
2. Bring up the Bitesize solids and liquids activity on the interactive whiteboard.
3. Show the children: 1) how to place a different substance into the container, 2) how to heat the substance, 3) how to cool the substance, 4) where to watch the changing temperature display, 5) how to test the substance.
4. Divide the class into groups with a computer for each group. Ask the children to heat and cool each of the substances in the menu and to record the melting point of each for discussion later.

Plenary

1. Ask the following questions: Do all solids melt at the same temperature? Which order do the solids you tested melt in? Which of the solids you tested do you think would melt on a hot day?
2. Remind the children that they have learned that solids can become liquids when heated to different temperatures. Ask them when they think this property would be useful (eg melting wax to shape candles, moulding molten metal or plastic).

Extension

1. Ask the children to construct a graph of the melting points of the materials they tested and to devise statements and questions that can be displayed for others to investigate.
2. Alternatively, ask the children to complete the Solids and liquids worksheet (PDF 58KB) or the Bitesize solids and liquids quiz.

Homework

1. Ask the children to compile a list of useful changes of state as observed in their homes (eg melting butter) and to bring the list to school to compare and discuss with the class.
2. Alternatively, play the Pod's Mission solids and liquids game.