EARLY SCIENTISTS Early scientists did

not know about the three states of matter so they believed that all elements were made from earth, air, fire and water.

TODAY SCIENTISTS KNOW!

There are four states of matter.

Solid Liquid Gas Plasma

GAS A gas has no definite

shape . Particles of a gas

move quickly, so they can break away from one another.

The amount of empty space between particles can change, so A GAS CAN VARY IN VOLUME!

EXPERIMENT Blow up a balloon but

not too full. Tie it off. Mark on the balloon

where you will measure the circumference with permanent marker.

Measure the circumference.

Leave the balloon outside in the cold for 10 minutes.

Measure it again. What happened? Why?

HOW DOES A HOT AIR BALLOON OPERATE?

How do the floats in parades compare?

Gas behavior Volume can

change due to temperature and pressure.

Helium The amount of

helium used to fill a parade balloon depends on the outside temperature.

VOLUME Volume is the amount

of space an object takes up.

The volume of gas depends on its container.

If you tried to shape a balloon with gas, it would work

But if to tried to ahpe a balloon filled with water, it would explode!

PRESSURE Pressure is the

amount of force exerted on a given area of surface.

Pressure of a gas is the number of times particles of a gas hit the inside of their container.

BASKETBALL A basketball has

MORE particles of gas, closer together hat collide at a faster rate.

That is why it feels firmer.

BEACHBALL A beachball has

FEWER particles of gas, further apart, and the particles collide at a slower rate.

It feels softer. BUT it has the

same volume of air as the basketball.

SCIENCE BOOK Gas Demo Book Page 70