1. a small glass bottle with a tightly fitting cork
2. baking soda
3. vinegar
4. a piece of paper
5. water

Now this is step by step :
Put some baking soda into bottle
Dip the cork in water to make it very wet.
Pour some vinegar into the bottle and push in the cork as quickly as you can.
And…Stand Back…!!! The cork will Pop Out!!!

So, How it works?

This is a little explanation about why the cork pop out..
Baking soda is a chemical called sodium bicarbonate. When this stuff mixes with vinegar, it makes a gas called CO2 or Carbon Dioxide. This gas pushes the cork out of the bottle. Most explosives work because a special mixture of chemicals makes a huge amount of gas quickly.

And DO YOU KNOW that some rockets work in the same way with this basic experiment? The fuel in the rockets makes a big blast of gas that can pushes out the end of the rocket and sends it up and along into space.

Incoming search terms:

• how do rockets work
• make a gas cannon

• glass jar
• bowl
• spoon
• a long piece of thread
• paper clip
• washing soda
• very hot water
• pencil

Now this is the experiment :

1. Put the spoon into the clean jar, to stop the hot water cracking the jar. Fill the jar with hot water..(please be careful..).
2. Put several teaspoons of washing soda into the water and stir until it has all disappeared. Put in more soda and stir again.
3. Stand the jar in a bowl of very hot water in the jar hot. Spoon in more soda and stir it again until no more can disappear in the water.
4. Now..this is the interesting…tie a paper clip to one end of a piece of thread and tie the other end round a pencil.
5. Drop the clip into the jar… and see what happens..
6. You can mix a few drops of poster paint or ink in the water to make the crystals have color.

If you leave the jar for a few days, the crystals will grow and you now can grow the crystals..