KEY IDEAS

• Air takes up space
• Air is a mixture of gases
• Air is all around us

EXAMPLE QUESTIONS

• What do you think air is?
• How can you tell air is present?
• Is there air in an empty glass?

AIR IS A MIXTURE OF INVISIBLE GASES

• Air is all around us.
• It is an invisible mixture of gases, and it takes up space.
• (An Empty drinking glass is not really empty; it is full of air).
• Air, or any gas, consists of tiny moving particles, called molecules.

AIR TAKES THE SHAPE OF CONTAINERS

• Air takes the shape of the container that holds it.
• Balloons and bubbles have captured air inside them.
• Inflatables maintain their shape because of the air inside them.
• Molecules of the gases, that make up air, move around independently of each other throughout all the available space.