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�鶹������ҳ��� Teach > Primary resources > KS2 Science > Experiments in controlled environments

Video summary

It’s time for a picnic and presenters Harry and Frankie want to take some ice with them to keep their food cool.

However, ice melts really easily. So, they investigate whether wrapping ice in a material stops if from melting and if so, which material works best?

To do this, they set up a comparative test.

In the test, the change variable was the type of material used to wrap the blocks; the measure variable was the weight of the ice.

This short film is from the �鶹������ҳ��� Teach series Experiments in controlled environments.

Teacher Notes

Before Watching

Ask your learners which foods they like to take on a picnic or have in their packed lunches? How do they keep those foods cold? Why is it good to keep food cool?

Imagine you are going to test some materials – bubble wrap, fabric, foil and no material to see which one keeps an ice block frozen. Which one do you think would work best? Why?

Materials that don’t conduct heat well are called insulators. Ask the children how an insulator might help keep food fresh?

After Watching

Look at the table of results again. What conclusions can you draw from this data? Why was bubble wrap the best material for keeping the ice from melting? Ask the children to rank the results from best to worst. How much larger was the ice block when wrapped in bubble wrap, compared to the ice block without any wrapping?

The bubble wrap is a good insulator. Ask your children to explain how the bubble wrap was preventing the ice from melting too quickly. Ask your children to think about other places where they see insulation? Have they got a food or drink container with insulation? Which materials are used as insulators?

Try out this investigation. Can you find any other materials that are good insulators?

Key Scientific Knowledge

• Insulation – thermal insulation consists of materials that conduct heat poorly. Many good insulators are made of non-metallic materials filled with tiny air spaces. Insulation, reduces the movement of energy in either direction.

• Melting - heat melts a solid and turns it into a liquid.

Developing Practical Enquiry Skills

• Comparative test enquiries - comparative test are an opportunity for children to make comparisons. In this case we are comparing materials. To set up a comparative test we change one variable, measure another variable and keep all the other variables the same.

• Variables – these are factors that could be controlled or changed as part of an experiment. In a fair or comparative test there is one change variable (independent variable), one measure variable (dependent variable) - the variable being measured or observed. All other variables are controlled and kept the same.

• Constructing a table – tables are an important tool for collecting and organising information. Tables are made of columns and rows. Usually, the change variable (independent variable) is recorded in the left-hand column. The right-hand column records the measurements or observations (dependent variable). Each column should be labelled, including the units of measurement as appropriate.

• Conclusion - To draw a conclusion is to make a judgement based on the evidence you have gathered. A conclusion includes a summary of whether any patterns were spotted in the data; plus, an explanation of the findings using appropriately scientific language.

Ideas for further learning

Some materials work better as insulators if they are used in combination with another material or if you use more than one layer. Ask your learners to investigate which combination of materials might work together to keep an ice block frozen for even longer.

These short film clips support teachers with practical enquiry. They can be both used as a resource for learners to watch at home. Or as a stimulus to support learners to plan and conduct their own science investigations. They link to the UK Science curricula.

Materials

• Pupils group materials together, according to whether they are solids, liquids or gases.
• Pupils observe that some materials change state when they are heated or cooled, and measure or research the temperature at which this happens in degrees Celsius (°C).

Science enquiry / Working scientifically skills

• Pupils should plan different types of scientific enquiries to answer questions, including recognising and controlling variables where necessary.
• Pupils should take measurements, using a range of scientific equipment, with increasing accuracy and precision, taking repeat readings when appropriate.
• Pupils should record data using tables.

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