 |
| Same Stuff, Different Forms. SOLID, LIQUID AND GAS. |
Do
you know that many of the things you may see or use every day – such as the
water in a glass, the air in a football, and even the hard metal in a toy car –
are potential transformers?
The substance that these things are made
of can take the form of solid, a liquid, or a gas. The form they take mostly
depends on their temperature. When water gets cold enough, it become a hard
solid we call “ice”. When it get hot enough, it becomes a wispy gas we call
“steam”. Many other substance behave the same way when they are heated or
cooled enough.
A solids hold its own size and shape
without needing a container. If you pour water into an ice tray and freeze it,
the water will keep the shape of the cube-shaped molds in the tray. You can
think of solid metal in a toy car as frozen too, but its melting temperature is
much higher than the temperature we live in. The person who made the car poured
very hot liquid metal into a car-shaped moulds and let it could down and
freeze.
A liquid does not hold its own shape. If
you pour a half liter of water into a tall vase or a shallow bowl, it will take
the shape of its container. But that water does keep its own size. It measures
a half litre. Everyday liquids such as milk, paint and petrol act this same
way.
Gases do not keep their own shape or
their own size. When air is pumped into a football, it takes the shape and size
of the ball. As more air is pumped in, the ball gets harder but not much
bigger.
The air changes its size to fit the
space inside the ball.
0 Comments