1.Effect of Change of Temperature:
Solid to liquid: On increasing the temperature of solids, the kinetic energy of the particles increases which overcomes the forces of attraction between the particles thereby solid gets converted to a liquid.
Melting: Change of solid state of a substance into liquid is called melting.
Melting point: The temperature at which a solid melts to become a liquid at the atmospheric pressure is called its melting point.
Melting point of ice is 0°c.
Liquid to gas: On heating a liquid like water, the kinetic energy of its particles increases as high as in a gas, thus causing the liquid to change to a gas.
Boiling: The change of a liquid substance into gas on heating is called boiling.
Boiling point: The temperature at which a liquid boils and changes rapidly into a gas at the atmospheric pressure is called its boiling point.
Boiling point if water is 100°C.
Gas to liquid: On cooling a gas like steam (or water vapour), the kinetic energy of its particles is lowered down, causing them to move slowly and bringing them closer, forming a liquid.
Condensation: The process, in which a gas, on cooling, turns into a liquid at a specific temperature is called condensation or liquefaction.
Liquid to solid:
When a liquid is cooled down by lowering its temperature, its particles lose the kinetic energy and come to a stationary position, causing the liquid to turn to solid.
Freezing: The change of a liquid substance into solid by lowering its temperature is called freezing.
Freezing point: The temperature at which the state of a substance changes from a liquid to a solid is called the freezing point of that substance.
Fusion: The process of melting, that is, change of solid state into liquid state is also known as fusion.
Latent heat: The heat energy that is required to change the state of a substance without causing any ruse in the temperature of the substance is called latent heat. Since, the heat energy is hidden in the bulk of the matter, it is called latent heat.
Latent heat of fusion: The heat energy required to convert 1 kilogram of a solid into liquid at atmospheric pressure, at its melting point, is known as the latent heat of fusion.
Latent heat of vaporisation: The heat energy required to convert 1 kilogram of liquid into gas, at atmospheric pressure, at its boiling point, is known as the latent heat of vaporisation.
Water vapour at 373 K have more energy than water at the same temperature because particles in steam have absorbed extra energy in the form of latent heat of vaporisation.
Sublimation: The change of state of a substance directly from a solid to gas or gas to solid, without changing into the liquid state, is called sublimation.
Shaalaa.com | Changes in states of matter
A few substances are arranged in the increasing order of 'forces of attraction' between their particles. Which one of the following represents the correct arrangement?