This activity was created by the NASA/JPL Project Space.

What You'll Need:

• safety goggles
• a piece of chalk
• newspaper
• a hammer
• a nail
• a medium-sized jelly or pickle jar with a lid
• a lid (extra large so that it is able to rest on top of the jar)
• hot tap water
• a watch or a clock (to be used as a timer)
• 2 - 3 ice cubes

Procedure:

Step 1:
Place the piece of chalk on the newspaper.

Step 2:
Put on your safety goggles.  Pound the chalk with the hammer to make fine powdery chalk dust.

Step 3:
Set the chalk dust aside.  Try not to breath in the dust.

Step 4:
Use the hammer and nail to punch holes in the extra-large lid only.  The holes should cover the entire lid.

Step 5:
Fill the jar with the hot tap water.

Step 6:
Cover the jar with its lid.  Let the jar stand for 2 minutes.

Step 7:
Remove the lid and pour out 90% of the water (make your best estimate).

Step 8:
Place the extra-large lid with the holes in it on top of the jar.

Step 9:
Put the ice cubes on top of the lid.  Let the jar stand for about 3 minutes.

Step 10:
Remove the ice cubes and the extra-large lid.  Sprinkle a pinch of chalk dust into the jar.  Cover the jar tightly with its lid.

Step 11:
Observe the inside of the jar after about 2 minutes.  A cloud has formed.

Step 12:
Answer the following questions.  How were the water droplets formed? How did the chalk dust help to form the cloud?