3rd Class Science Matter and Materials Matter

       Matter

Every day we see various things around us. Some of them are heavy, for example, 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 water bottle, all occupies 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 stages of matter.  

         Solid

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 object.

        Liquid

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

         Gas

Observe when your mother boils water. You will see that some vapour is rising from the boiled water. Now, ask your mother to hold a plate on the rising vapour.

You will find little droplets of water have been formed on the plate.

It means that the vapour that was rising from the boiling water of the container is actually water. Water vapour is the gas form of water. A gas is a state of mater that has no shape and size of its own.

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

       Changes of State

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

The process of changing solid into liquid is called

The process of changing liquid into gas is called

The process of changing a gas into liquid (for example, water vapour to water) is called

The process of changing a liquid into solid is called

Ice is frozen water.

Ice cream is frozen milk.

    What is matter?

(a) Anything that has mass                         

(b) Anything that occupies space

(c) Anything that has mass and occupies space

(d) None of these

(e) All of these

Answer: (c)

Explanation

Matters are the objects that occupy space and have mass in other words anything that has mass and occupies space is called matter.

There are _______________ states of matter.

(a) 2  

(b) 4

(c) 3  

(d) 1

(e) None of these

Answer: (c)

Explanation

There are three states of matter, that is, solid, liquid and gas.