Page 119 - DK Children's Encyclopedia

Gases SEE ALSO

▸ ▸ Changing states
p.57

Gases are all around us—we are surrounded by a ▸ ▸ Elements p.90
mixture of gas called air. We can keep them in sealed ▸ ▸ Liquids p.148
containers but if we open the container, the gas ▸ ▸ Lungs p.149

escapes and spreads out. Most gases are invisible. ▸ ▸ Mixtures p.168
▸ ▸ Solids p.234

Helium is a
lighter gas than
What gases do air, so helium
balloons float.
Gases have things they
do called properties. For
example, gases can be
squashed and then they
push back to fill the original
space. This is useful for
pumping up bike tires
that cushion bumps in
the road as we ride.

Blowing bubbles
Soap bubbles contain a little

Gases bit of air that pushes out
expand toward the bubble. The soap
to fill their bubble mix is stretched but
container.
pushes back, squashing the
air into a sphere.

Fizzy drinks
When you see bubbles in a
liquid, every one of them is
Gas would
escape from an full of gas. In a fizzy drink,
unsealed container. the bubbles are the gas
carbon dioxide.
Gas particles
Gases are made from tiny
particles that move away What’s in air? 1% other gases
from each other in all Air is the gas all around
directions at top speed. us. It is made of a
They travel long distances mixture of different 78%
unless they bounce off gases, but mostly a nitrogen
solid barriers. gas called nitrogen.
We breathe in oxygen 21% oxygen
from the air for our
bodies to use.
The gases in air

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