Matter in Our Surroundings

Anything in the universe which occupies space and having mass and volume is called MATTER.

Matter is made up of small particles.

The particles of matter are moving continuously, that having motion.

There is space between particles of matter.

The matter around us exists in three states- solid, liquid and gas.

Solid: Matter having fixed volume, mass and definite boundary, i.e. fixed shape is called Solid.

Liquid: Matter having fixed volume and mass but not fixed shape is called Liquid. A liquid gets the shape of the container in which it is kept.

Gas: Matter having no fixed volume or shape but has fixed mass is called Gas. A gas takes the volume and shape of the container in which it is kept.

Particles of a matter are bonded together with a force called force of attraction, which keep them together.

The forces of attraction between the particles are maximum in solid, intermediate in liquid and negligible in gas.

Since, force of attraction between particles is maximum in solids; that is why a solid has fixed shape, volume and mass.

The force of attraction between particles is intermediate in liquids because of that a liquid has fixed volume and mass but don't has fixed shape. A liquid gets the shape of the container in which it is kept. Because of less force of attraction between particles, a liquid flows.

The force of attraction between particles is negligible in the case of a gas, this is the cause that a gas has fixed mass but don't has fixed volume or shape. A gas acquires the shape and volume of the container in which it is kept.

The spaces in between the constituent particles and kinetic energy of the particles are minimum In the case of solid, intermediate in liquids and maximum in gases.

Because of maximum kinetic energy of particles of gas, particles of gas move in all direction freely and they exert pressure on the wall of container in all of the directions in which a gas is kept.

The arrangement of particles is most ordered in the case of solid, in the case of liquid layers of particles can slip and slide over each other while for gases, there is no order, particles just move about randomly.

The states of matter are inter-convertible. The state of matter can be changed by changing temperature of pressure.

Change of solid into liquid

A solid can be changed into liquid by applying heat energy.

Sublimation is the change of gaseous state directly to solid state without going through liquid state, and vice versa.

Boiling is a bulk phenomenon. Particles from the bulk (whole) of the liquid change into vapour state.

Evaporation is a surface phenomenon. Particles from the surface gain enough energy to overcome the forces of attraction present in the liquid and change into the vapour state.

The rate of evaporation depends upon the surface area exposed to the atmosphere, the temperature, the humidity and the wind speed.

Evaporation causes cooling.

Latent heat of vaporization is the heat energy required to change 1 kg of liquid gas at atmospheric pressure at its boiling point.

Latent heat of fusion is the amount of heat energy required to change 1 kg of solid into liquid at its melting point.