Solids, Liquids and Gases

1. By Aniruddh Kommajosyula
III C
Delhi Public School, Nerul

3.  Things like pen, pencil, and eraser have a
fixed shape and size.
 They do not flow and cannot be poured into
containers. Such things are called Solids.
 However, powders such as talcum powders
and table salt can flow and take the shape of
the container they are put in.

4.  Things like water, oil, and milk do not have a
fixed shape.
 They flow easily and take the shape of the
container they are poured into. Such things
are called liquids.

5.  A thing that has no shape or size of its own is
called a gas.
 Water vapour is a gas. Most gases cannot be
seen.
 We breathe in air rich in a gas called Oxygen.
 Living things need oxygen.
 Gases are all around us. Air is a mixture of
many gases.
 Air moves from one place to another.
 Moving air is called wind.
 Like liquids, gases can also flow.

6.  Solids have a fixed
or definite shape.
 Solids do not flow
easily.
 Liquids do not have
any definite shape.
They take the shape
of the container.
 Liquids flow easily.

7.  Water freezes to form ice.
 Ice melts to form water.
 If we hold a lid or a plate above boiling water,
the steam touches the lid. The steam then
cools down and changes into tiny water
droplets. This is called Condensation.
 Steam condenses to form water.
 The three forms of water – solid, liquid and
gas – can change from one form to another.

9.  Aim: To observe condensation
 Materials needed: A steel or glass tumbler, and
ice-cold water
 Method:
 1. Keep ice-cold water in a steel or glass
tumbler.
 2. Leave it for 5min. What do you observe?
 Observation: There are water droplets on the
outer surface of the tumbler.
 Conclusion: There is water vapour in the air.
When the vapour comes in contact with the cold
surface of the tumbler, it cools down and
condenses to form water droplets.

10.  Solid: A thing that has a definite shape and size is
called a solid.
 Liquid: A thing that takes the shape of its container is
called a liquid.
 Gas: A thing that has no shape or size of its own is
called a gas.
 Melting: The process in which a solid changes into
liquid on heating is called melting.
 Evaporation: The process in which a liquid changes
into gas on heating is called evaporation.
 Condensation: The process in which a gas changes
into liquid on cooling is called condensation.
 Freezing: The process in which a liquid changes into
solid on cooling is called freezing.