manual

22
The air inside the test tube stops the water from rising.
78 parts are nitrogen
21 parts are oxygen
1 part is other gases
Air is a mixture of gases:
nitrogen, oxygen, carbon dioxide,
and small quantities of other gases.
In 100 parts of air:
The air particles take up space inside the
test tube and exer
t pr
essur
e so the water
can’t get up high enough to wet the
dollar bill.
The water level stops at the entrance
to the upside down test tube.
air