3rd Class Science Matter in Our Surroundings Matter

Matter

Matter

Everyday we see various things around us. Some of them are heavy, for example, I computer. Some of them are light, for example, your pencil. This is because, different objects have different masses. The mass of an object tells us whether an object is heavy or light, or how much heavy or light.

Every object also occupies space. For example, books in your school bag, pencils in your pencil box, water in your water bottle, all occupy space.

Anything which has mass and occupies space is called matter.

Matter exists in three different forms:

(i) Solid                        (ii) Liquid

(iii) Gas

These three forms of matter are called the states of matter.

Solids

Objects like books, pen, pencil, cricket bat, doll, tiffin box, school bag, etc have a fixed shape. They do not change their shape if we move them from one container to another. They are called solid objects.

Liquids

Substances such as water, milk, oil, etc can flow easily and change their shape according to the shape of container they are kept in. Such materials are called liquid objects.

Gas      

A gas is a state of matter that has no shape and size of its own. Observe when your mother boils water. You will see that some vapours are rising from the boiled water. Now, ask your mother to hold a plate on the rising vapours. You will find that little droplets of water have been formed on the surface of plate.

It means that the vapours which were rising from the boiling water of the- container was actually water. Water vapour is the gaseous form of water.

You know that we all inhale oxygen. Oxygen is a gas. Gases are all around us. We cannot see them. They are invisible.

Changing States of Matter

The three states of matter are solid, liquid and gas which can change their form from one to another.

• The process of changing solid into liquid is called melting.
• The process of changing liquid into gas is called evaporation.
• The process of changing a gas into liquid is called condensation.
• The process of changing a liquid into solid is called freezing

Ice is frozen water.

Ice creams frozen milk.