Page 259 - New Medley 5 Semester 2

STEM ACTIVITY 1

Observing the role of air in burning
 Take a lighted candle and place a small glass over it.
 Observe the ame for a few seconds.

 Notice that the candle ame went out quickly a er being covered.

 Repeat the activity using a bigger glass over a new lighted candle.
 Observe that the candle burns for a longer time before going out.

 You will see that the di erence is amount of air (oxygen) inside
each glass.

e smaller glass has less oxygen, so the ame went out quickly.
But, the bigger glass has more oxygen, so the ame lasted longer.

STEM ACTIVITY 2
Exploring the presence of air in an empty glass
 Take an empty glass.
 Turn the glass upside down.
 Place it vertically on the surface of water in a tub.
 Gently press the glass down into the water while keeping it straight.
 Observed that water do not enter the glass.

 e glass is not truly empty—it is lled with air, which prevents water from entering the

glass.
STEM ACTIVITY 3

Making a model of sedimentary rock
 Collect the following materials:
1 cup of water
½ cup of Epsom salt (hydrated magnesium sulphate)
A small paper cup
Some amount of sand
 Mix the water and Epsom salt in a bowl.
Stir the solution until most of the salt dissolves in water.
 Place about 1 inch of sand into the paper cup.

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