# The iceman cometh...

23rd January 1998 at 00:00
Emma Burstall finds out how to turn the cold logic of insulation theory into a really cool science lesson

Those people who think science is dull should take another look in the classroom. At its best, it is a highly imaginative subject that allows children to continually create new pictures in their heads to make sense of what's going on in the world around them.

Anne Goldsworthy, who chairs the Association for Science Education's primary committee, says: "Science gives young pupils the chance to say: 'I reckon this is what's going to happen and I'm going to try it out and see.'" She recommends using the ice hand experiment shown here to demonstrate how water changes state and how insulation works, and says that children as young as four or five will grasp complex scientific concepts like this much faster if you give them a gripping story and strong visual stimuli.

You can invent a story about an ice man who does not want to melt and tell the children you will bring his spare hands in to show them. Their task is to try and help him stay frozen.

Adults often tell youngsters to put their coats on to keep them warm. As a result, children sometimes think the material in their clothes possesses a magic property that keeps out the cold. So they assume that if they put a coat on a snowman, for example, it will become hot and melt faster.

Pupils need to find out that heat will always be conducted from a warm object to a colder one. Then they can discover how insulating materials act as a barrier, slowing down the passage of heat to keep an object at a more stable temperature - if you wrap a lump of ice in bubblewrap it will melt less quickly than a piece of ice left in the warm air.

When they discover that the ice wrapped in insulating material stays solid longer than a piece of ice exposed to the air, they will soon understand that the insulating material cannot be heating the ice up.

You will need a pair of long-cuffed washing up gloves and some strong elastic bands (if your school kitchen has a freezer, the children can help with steps 1-3)

1. Take a jug of water and fill both gloves almost to the top, carefully making sure you expel all the air as you would when filling a hot water bottle. Seal the tops with elastic bands, then leave in the freezer overnight

2. When the hands are properly frozen, you are ready to start the experiment. Run the gloves under some warm water for a few moments, then cut them off. Take care, the ice fingers are brittle and may break if you are too rough

3. Bring both of the ice hands into your class when they are properly frozen. Ask the children to help you carefully wrap one hand in several layers of a good insulating material, such as foam or bubblewrap. Leave the other hand uncovered to act as a control, then place the hands side by side in two large, plastic storage trays and see which melts first - the insulated hand or the uninsulated one

4. Ask the children to predict which hand will melt first and record what happens. As well as timing the experiment you could make a photo (or video ) record for a display.When the unwrapped hand has melted, take the insulating material off the other hand and discuss what has happened. Once the experiment is completed, you can put the melted ice back into the freezer to show that the process is reversible

THE ICEMAN ACROSS THE CURRICULUM

* Maths: cut string for pupils to wrap around the newly uncovered ice hand's palm and repeat throughout the day. The children stick the string to bits of paper and see how the pieces get smaller as time progresses.

* Drama: the children think of words to do with ice (cold, hard, shiny, sharp, frozen) and water (runny, wet, flowing). Put pupils into groups and ask them to pretend they are water that turns to ice. The pupils repeat their words very fast and move together until the teacher can't push through them. Then they gradually become flowing water again, running all over the place.

* Literacy: find poems and books on ice, snow and water, such as Raymond Briggs's The Snowman books (Puffin, Pounds 3.99 each).

* Nursery ideas: these activities can be adapted for younger children. They can observe how ice turns to water, conduct a floating and sinking experiment, and find out what happens when they hold ice and put salt on it. They can also experiment with ice pops, which bend when they are unfrozen but don't after they've been in the freezer. A nursery or reception class can devise an Antarctic home corner to develop language about cold climates.

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