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Science Y3/Y4 – Weather – week 9

WEATHER – THUNDER AND LIGHTNING

Truth to Teach (Source)

To investigate the causes of thunder and lightning.

To appreciate that lightning is a form of static electricity.

To learn about lightning conductors and the story of Benjamin Franklin.

To learn how to be safe in a thunderstorm.

Way to Work (Means)

1. Review the lessons on clouds and the water cycle.

2. Ask the children who has ever been out in a thunderstorm. Read Exodus 9:23-26, 29,

having given the introduction to the story. This shows that God can change the weather in
response to prayer. Ask how the children think Moses must have felt in the storm. Some
children may admit to being afraid of thunderstorms so prayer could be offered at the
end of the lesson. Talk about the safe place to be a storm.

3. Establish how much the children already know about thunder and lightning. Some may like
to look it up in books or on the Internet. Ensure that they know that lightning is caused by
static electricity. Compare this to flashes and sparks of light seen when you undress in
the dark. It may be due to nylon and woollen clothes rubbing together. Refer to the
experiment on the worksheet.

4. Tell the story of Benjamin Franklin who wanted to discover more about lightning, stressing
the danger of his actions. As a result of his dangerous experiment lightning conductors
were invented. Explain what these are – strips of metal going down the side of tall
buildings to carry the lightning safely to the ground.

One day Benjamin flew a large kite on a very long line up to a black storm cloud. He tied a
big iron key to the bottom of his line and when the electrical charge from the cloud ran
down the wet kite line and hit the key, sparks flashed. Thankfully, he was not hurt but he
could have been killed.

5. Draw a cloud on the board and explain that in a storm cloud the moving air makes tiny

water droplets and ice particles rub together so that they become charges with static
electricity. The positive charged particles rise to the top of the cloud and the negative
ones fall to the base of the cloud. The negative charges are attracted to the ground.
They leap from cloud to cloud or from the cloud to the ground, as giant flashes of
lightning. The lightning makes the air so hot that it explodes with loud booms of thunder.

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