States of Matter
* Solids have definite shape, volume and cannot be compressed.
* Liquids flow, have definite volume and take the shape of the container.
* Gases do not have definite volume, but take the shape of the container.
* Particles of matter are small in size and have space between them.
* In solids, particles have high force of attraction and less inter-molecular space.
* In liquids, particles have less force of attraction and more inter-molecular space
* In gases, particles have less force of attraction and large inter-molecular space.
Inter-conversion of States of Matter
* Inter-conversion of states is the phenomenon of the change of matter from one state to another and back to original state, by altering the temperature.
* The process where a solid changes to a liquid is called melting.
* Latent heat of fusion is the amount of heat energy required to change 1 kilogram of a solid into liquid.
* The process where a liquid changes to gas at its boiling point is called vaporisation.
*Latent heat of vaporisation is the amount of heat required to change a unit mass of liquid to gas at atmospheric pressure.
* Evaporation is the process where a liquid changes into vapour at any temperature below its boiling point.
The factors effecting evaporation are:
* Surface area
* Temperature
* Wind speed
* The process where vapour changes into a liquid is called condensation.
* The process where a liquid changes into a solid is freezing.
* Sublimation is the process where a solid, on heating, directly changes into gas without changing into liquid, and a gas on cooling directly changes to solid without changing into liquid.
* Applying pressure and reducing temperature can liquefy gases.