Bulletin Board

Experiments with air

At State Scientist Day in Sacramento, students watch chemist Eric Walton put 20 balloons in a steaming jar. How did he do it?

The jar is filled with liquid nitrogen which is extremely cold. It's much colder than inside your freezer. When the air inside a balloon gets very cold, it takes up less space. The balloon shrinks to the size of a quarter. When the balloon is removed from the liquid nitrogen, the air in it warms up and starts to take up more space. The balloon puffs up to its original size. Ms. Sharon Davis, the wife of California's governor, is standing next to Eric. She was amazed too.

Earth Day

Kids toss bean bags at the Air Resources Board's Earth Day booth at California State University at Sacramento.