Matter in our Surroundings

Matter in our Surroundings

Meaning of Matter in science –

Ø Everything in the universe is made up of material, which are called “Matter”

Matter is made up of small particles.

Examples-Air, Foods, Stone, clouds, Animals, Water, Evan a particles of sand etc

            Classification of Matter based on their physical properties-

(1)- Physical Nature of Matter – Matter is made up of particles. the particles of matter are very small. they are small beyond our imagination!!!

(2)-Characterises of particles of Matter -   Particles of Matter have space between them, particles of matter are continuously moving. Particle of matter attract each other.

(3) States of Matter – Matter around us exists in three different states. i.e. Solid, Liquid, Gas.

(a) Solid state- Solid matter are those Matter which have definite shape, size and volumes.

Examples- Pen, Book, Needles, Board, Bench etc

(b) Liquid state- Liquid Matter are those Matter which have fixed volume. Liquid Matter do not have fixed shape.

Examples- Water, Cooking oil, Milk, Juice, Cold drink etc

(C) The Gaseous State- The LPG, CNG (Compressed Natural Gas) , Oxygen etc , are the examples of Matter in Gaseous State. The Gaseous Matter are highly compressible as compared to Solid and Liquids Matter. In the Gaseous state, The Particle move about randomly at high speed.

(4) Can Matter Change its State?

(a) Due to effect of change of temperature- On increasing the temperature of solids, the Kinetic energy of the particles increases. Due to increase in Kinetic energy, the particle start vibrating with greater speed. The Energy supplied by heat overcomes the forces of attraction between the particles. The Particles have their fixed position and start moving more freely. A Stage is reached when the solid melts and is converted to a Liquid. The Minimum temperature at which a solid melt to become a liquid at the atmospheric pressure is called its melting point.

v Melting point of ice is 273.15K

v The Process of Melting , That is change of solid state into liquid state is known as Fusion.

v Latent Heat of Fusion- The Amount of Heat energy that is required to change 1 KG of solid into liquid at atmospheric pressure at its melting point is known as

(5) Evaporation- We know that particles of matter are always moving and are never at rest. At a given temperature in any gas, liquid, or solid, there are particles with different amount 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 the other particles and gets converted in Vapour. This Phenomenon of change of a liquid into vapours at any temperature below its boiling point is called Evaporation.

v The rate of evaporation increases with, an increase of surface, Temperature, wind speed etc. and also increases with the decrease of humidity.