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MeltingAimIn this activity, children explore melting of ice, jelly and chocolate. They learn that something doesn't have to be cold to melt - introducing the concept that melting involves warming something up.

What you’ll need Ice cube trays Large plastic tubs e.g. margarine or ice cream tubs Large trays or washing-up bowls Warm water Leaf gelatine and food colouring (or packets of jelly, but beware sweet jelly may get eaten) Small plastic toys optional Chocolate buttons Paper towels for mopping up spilled water

To prepare in advance Prepare lots of ice cubes in the trays. Also prepare some large ice cubes. You can even make strangely-shaped ice cubes if you freeze water in things like plastic gloves, or jelly moulds. You can freeze small plastic toys like plastic animals inside the giant ice cubes.

Prepare jelly squares using leaf gelatine and food colouring (or packet jelly). Cool overnight in a fridge.

IntroductionGet the children to think of things that are cold. Have some pictures printed ready to stick up on the wall. You can download a pdf file with large versions of all these free images at https://chembam.com/online-resources/pre-school-resources/melting/

Then introduce the concept of melting by sticking up a picture of the sun and asking questions like:

what happens to your snowman when the sun comes up? what happens to your ice cream on a hot day?

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It’s nice once you’ve introduced the concept of melting to have the letters of the word ready to pin up on a wall or noticeboard. With older children you could spell out the word. With younger ones perhaps just ask them what letter it starts with. A file with large letters is available on the link above.

Melting activity 1: ice cubesNow for the fun activities! Melting ice cubes is great fun in itself and we've found it will keep pre-schoolers amused for quite a long time. Make sure you have a big stock of ice cubes ready! We found the most popular activity was dipping ice cubes in large bowls of warm water. The children love feeling the ice cubes get smaller and gradually disappear.

Melting activity 2: giant ice cubesGiant ice cubes are also fun. We froze small plastic toys into large blocks of ice and the children have a lot of fun retrieving the toys.

A great idea is to use washing-up bottles or similar filled with hot water to melt giant ice cubes to make sculptures. Try adding colour by dropping some food dye into your water before freezing it. Another idea is to make strange-shaped ice blocks by freezing in things like gloves or jelly moulds.

Melting activity 3: jellyTo extend the activity, it's nice to use materials other than ice. Jelly melts easily in warm water and can be used to show children that other things can melt too. Jelly is also great fun to play with. We use leaf gelatine (or a vegetarian equivalent like agar) and food colouring to make jelly cubes in ice cube trays. You can use jelly/jello packets but the children might then eat it... Let the children experience the jelly melting away in their fingers in a bowl of warm water.

Again it's fun to trap little plastic toys inside the jelly. This could be a nice Halloween activity with plastic insects or spiders.

Background for teachers: Something to note here (although too advanced for pre-schooolers) is that jelly will also dissolve in water. We are using warm water as a way of getting heat into the jelly. But as it melts it will dissolve into the water. The key point is that the jelly would melt however you warmed it up. In fact, the reason that gelatin sweets have such a nice texture is that they melt at about body temperature i.e. 'melt-in-the-mouth'!

Melting activity 4: chocolateA slightly more advanced concept is that things don't have to be cold to melt. Chocolate isn't cold like ice but it will melt if you warm it up. The key lesson here is that melting happens when you warm things up. Chocolate buttons or chocolate chips will melt if you hold them in your hand. This is an optional (slightly more messy) extra that has been very popular with pre-schoolers in our experience!

Extension activity

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For older children, you could give them bowls of cold and hot water and ask them to guess which will melt the ice cubes fastest.

If you're lucky enough to get some snow during the winter, you can bring that inside too. Get the children to compare fluffy snow to the big ice blocks. How fast does the snow melt in warm water?

VocabularyIceMeltingCold, hot, warm

This work is licensed under the Creative Commons Attribution 4.0 International License. You are free to share and adapt the material for any purpose but please acknowledge the ChemBAM project