Free PDFGrade 5 · Science · 40 min

Haunted candle

Trap a flame under a glass and watch the water creep up.

I can explain what a flame needs and why the water rises under the glass.

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A science experiment video with a free worksheet and answer key for teachers

Worksheet Answer key

About the video

In the video a glass is lowered over a burning tea light, the flame goes out and coloured water creeps up inside the glass. At home your child repeats it with a bowl of 150 ml coloured water, times how long the flame lasts under a big and a small glass, and marks the water level with tape.

A flame needs fuel, heat and oxygen, so it goes out when too little oxygen is left under the glass. The water rises mainly because the hot air under the glass cools and shrinks after the flame dies, and the air outside then pushes water up into the glass.

What your child learns

Name the three things a flame needs to burn
Time and compare results from three tries
Explain how cooling air lets outside air push water up

What's on the worksheet

1Predict first
2Record your tries
3What did you see?
4The science behind it
5Match the words
6True or false
7Count with air
8Draw and label it

You need

1 tea light, 1 shallow bowl or deep plate, 150 ml water, 3 drops of food colouring, 1 tall clear glass (about 300 ml), 1 small clear glass (about 150 ml), a strip of tape, a timer, matches and an adult.