Teacher instructions

Work through this resource material in the following sequence:

20 minutes

Tune in: What will change?

20 minutes

Find out: Experiment time!

20 minutes

Reflection: What did we learn?

Tune in: What will change?

Step 1.

Discuss: what makes ice (or other solids) melt?

Students might suggest that heat has a large part to play.

Step 2.

Now discuss: how can we prevent, or at least slow, ice from melting?

Lead students to the idea that insulators to protect ice from the warm environment outside the freezer can slow the rate of ice melting. Students are likely familiar with the concept of an esky to keep soft drinks or foods cold during a picnic.

Step 3.

Finally, discuss: what kinds of materials would make good insulators? Would different materials have an impact on the rate of the ice melting?

Step 4.

Explain the experiment to your students.

Step 5.

Students write their predictions in the first section of the Student Worksheet.

Find out: Experiment time!

Step 1.

Take one cardboard box and line it with one of the materials. Repeat with the remaining cardboard boxes.

Step 2.

Place an equal number of ice cubes in each box.

Step 3.

Close the lids of the boxes, place them on a table or bench and set the stopwatch for half an hour.

Step 4.

Check the ice cubes every half hour and record which boxes make the best eskies!

Reflection: What did we learn?

Some materials are good thermal conductors. This means they easily let heat (meaning both hot and cold temperatures) pass through them.

Other materials are good thermal insulators, not easily letting heat pass through them.

For example, metal is a good conductor, and this is why it is great for saucepans, because the heat from the stove top heats up the saucepan quickly and gets to your food.

However, a saucepan handle is often made of wood or plastic because these materials are good insulators and therefore stop your hands being burned.

You can reduce the transfer of heat from the air to an object such as ice cubes through the application of insulation.

For example, by putting a tea cosy over a teapot you can help the teapot retain heat, as the loss of heat will be reduced.

The same works for keeping things cold. When we line the cardboard boxes with insulation, the heat from the outside environment, which will be warmer than the ice cubes (which are at 0 degrees Celsius), has to transfer through the insulating material. Depending on how well the material conducts heat energy, warmth gets through to the ice cubes more or less easily, and causes them to melt faster or slower.

How Can We Stop Ice from Melting?

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