Air Inside Water

You will need:

• a clear glass jar (transparent) / glass (transparent)
  
  
• transparent bowl or basin (deeper than jar) containing water
  

Steps:

1. Turn the jar upside down and put it inside the water (fast) until the jar's mouth touch the bottom of transparent bowl.
2. You can see the difference between water and air (inside the jar) from the color.
   The water color is a little bit blue, the air is transparent.
3. Open a side (only one side) of the jar so another side still touching the bottom of the bowl / basin. Keep open it in 0.5 second - 1 second then close it again then some water will be inside the jar but there is air (still) inside the jar.

What was actually we do?
We want to prove that air is everywhere, including in water.