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Matter and it’s compositionMatter is classified on the basis of physical & chemical properties.

Physical properties being solids liquids gases. Chemical properties –elements ,compounds & mixtures. Physical nature of matter is based on particles of matter. Particles mainly consists of molecules which consists of atoms . rain water contains 10 to the power 21 particles. Many evidences show that matter contain particles. It can be proved by diffusion & Brownian motion .for example if we open a perfume bottle at one corner of the room, It can be smelt in the whole room- it is because of diffusion. if a gas jar containing air is placed upside down on a gas jar of bromine vapour , both gases get equally mixed.

Matter is both rigid & fluid. Rigid-unbending & flexible. Fluid-can flow easily.Matter is mainly classified as physical & chemical. Physical –solids,liquids,gases.Chemical-elements,compounds,mixtures.Solids are classified as amorphous & crystalline.Mixtures are classified as homogenous & heterogenous.Solids have definite shape and volume.Liquids have definite volume but no definite shape.Gases have no definite shape or volume.

Change of state from- solid to liquid is called melting ,liquid to gas is called boiling-brought up by heating.Gas to liquid is called condensation,Liquid to solid is called freezing-brought down by cooling.Solid to gas or gas to solid is called sublimation-by heating or cooling.