Strand – Energy and forces

Strand Unit – Heat

Class – 3rd – 6th

In order for something to burn, it requires oxygen.

Prior knowledge required by students

Oxygen exists all around us, it is essential to us. Oxygen is produced by trees. Air can be heated and when is heats it rises. e.g. hot air balloon

Stage 1

Stimulus questions to engage the stuednts and get them interested

How can we prove that hot air rises?

What do you think will happen if a burning candle is placed under a jar?

Does the air we inhale contain more or less oxygen than the air we exhale?

Listen to an audio clip of the children questioning each other.     

Stage 2

The experiment

Materials needed – ( tray, candle, glass jar, matches, food colouring, water)

Divide the class into groups of 2 or 4.

Each group is given a tray/dish, candle, glass jar.

Secure the candle in the tray using some candle wax to fix it.

Half fill the tray with water and add some food colouring to turn the water red.

Light the candle, cover the candle with the glass jar and observe what happens.

Get each group to record how long it took for the candle to extinguish. 

Before carrying out the experiment, make sure that each groups’ predictions are clearly recorded.

Take a look at the following video to see how the experiment is carried out.

video – candleinwater

Stage 3

Learning outcomes

Investigate each group’s findings, ask the following questions

What caused the candle to extinguish?

For how long did the candle burn?

Why did we use coloured water?

What do you think caused the water to be sucked into the jar?

Listen to an audio clip of the children’s findings  

Conclusion

Provide each group with the opportunity to compare their predictions with the results and let each group share their findings with each other. Discuss how the children worked like scientists where they answered some research questions, planned an experiment and then carried out the experiment.