UNIT 4
Lessons 25~32
Look into Science!
Lesson 25:
Keep the Candle Burning!Science is so interesting!
I'm sure you'll like this experiment!
When you do this experiment,you will learn something about air!
What do you need?
a candle
a candleholder
a big glass jar
a shallow dish with water
matches
To make a candle burn,youlightit.What do you use?
A match.What do you do?
1.Put the candle in the candleholder.
2.Put the candle- holder in the dish
3.Fill the dish half full of water.
4.Light the candle.
5.Let the candle burn for two or three minutes.
6.Carefully put the jar over the candle.
7.Look at the water in the jar.What observation can you make?
What is happening?
As the candle burns,it uses up oxygen in the air.
When the candle stops burning it has used up all the oxygen in

the air.
The water inside the jar then rises.
How far did the water rise?Air is about one- fifth oxygen,
so the water rises and fills about one- fifth of the jar.