Matter in our in surrounding

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Contents : About Matter

Physical Nature of Matter Characteristics of Particles of Matter States of Matter Matter Changing its State Evaporation Multiple Choice Questions Some Interesting Pictures

About Matter Everything in this universe is

made up of material which is called Matter.

Matter is anything which occupies mass and space.

Each matter is a collection of lots of tiny particles.

Particles of matter are continuously moving.

Physical Nature of Matter Matter is made up of particles.

The particles of matter are very small - they are small beyond our imagination.

Characteristics of Particles of Matter Particles of matter have space between

them.

EXAMPLE : When we make tea or coffee, particles of one type of matter get into the spaces between particles of the other. This shows that there is enough space between particles of matter.

• Particles of matter are continuously moving.

- They possess what we call the Kinetic Energy. As the temperature raises, particles move faster. So, we can say that

with increase in temperature the kinetic energy of the particles also increases.

► Particles of matter attract each other.

- Particles of matter have force acting between them. This force keeps the particles together. The strength of this force of attraction varies from one

kind of matter to another.

States of Matter ►Matter around us exist in

three different states - (i) Solid (ii) Liquid (iii) Gas

The Solid State Solids have a tendency to maintain their shape

when subjected to outside force.

Solids may break under force but it is difficult to change their shape, so they are rigid.

The Liquid State Liquids have no fixed shape but

have a fixed volume.

Liquids take up the shape of the container in which they are kept.

The Gaseous State Gases are highly

compressible as compared to solids and liquids.

Matter Changing Its State

Effect of Change of Temperature

On increasing the temperature of solids, the kinetic energy of the particles increases.

Due to the increase in kinetic energy, the particles start vibrating with greater speed.

The energy supplied heat overcomes the forces of attraction between the particles.

The particles leave their fixed positions and start moving freely. A stage is reached when the solid melts and is converted to liquid.

The temperature at which a solid melts to become a liquid at the atmospheric pressure is called its Melting Point.

The melting point of a solid is an indication of the strength of the force of attraction between its particles.

The melting point of ice is 273.16K*.

The process of melting, that is, change of solid state into liquid state is known as Fusion.

The state of matter can be changed into another state by changing the temperature.

Evaporation Particles of matter are always moving and never at rest.

At a given temperature in any gas, liquid or solid, there are particles with different amounts of kinetic energy.

In the case of liquids, a small fraction of particles at the surface, having higher kinetic energy, is able to break away from the forces of attraction of other particles and gets converted into vapour.

• This phenomenon of change of liquid into vapours at any temperature below its boiling point is called Evaporation.

Made by: GauravIX –B‘10’