Melting |

Introduction activity

Melting is a fascinating concept for young children and they love getting their hands wet with this activity. States of matter doesn’t come into the curriculum until Year 4, but even young children easily pick up the concept of melting. We start our sessions by getting the children to think of things that are cold. We have pictures ready (printable versions below) to stick up or use as prompts.

We then introduce the concept of melting by sticking up a picture of a sun. We ask questions like:

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

Once you’ve introduced the concept of melting, it’s nice to have the letters of the word ready to pin up on a wall or noticeboard.

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

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. If you have children that are not able to touch gelatine, you can use a vegetarian equivalent.

Melting activity 1: Ice cubes

Now for the fun activities! Make sure you have a big stock of ice cubes ready and let the children spend time 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 cubes

Giant 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 nice idea is to make strange-shaped ice blocks by freezing in things like gloves or jelly moulds.

Melting activity 3: Jelly

To 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 if it tastes sweet the children might be tempted to eat it!

Place the jelly cubes in food bags and suspend the bags in hand-hot water to melt the cubes. You can hold the cubes directly in water but it’s important not to confuse melting with dissolving.

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: the reason that gelatin desserts have such a nice texture is that they melt at about body temperature i.e. ‘melt-in-the-mouth’.

Melting activity 4: Chocolate

A 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, or in a plastic food bag in a bowl of hot water.

Extension activities

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

You could also get them to time how long it takes to melt the jelly cubes in water of different temperature.

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?

pdf file of all the images for easy printing

pdf of the ‘melting’ letters for printing

Image attributions – all royalty free

Snowman, iced lolly, melted ice lolly and ice cube images by OpenClipart-Vectors from Pixabay
Ice cream image by Schmidsi from Pixabay
Igloo and melting ice cube images by Clker-Free-Vector-Images from Pixabay
Sun image by Karen Arnold from Pixabay
Melted ice cream image by Alexandra_Koch from Pixabay
Melted snowman from 101clipart