Matter can change from solid to liquid to gaseous state and back to solid state. This is called change of state of matter.
(a) Melting— The process of conversion of a solid into liquid on heating. e.g. Ice to water.
(b) Vaporization— The process of conversion of a liquid into vapour on heating. e.g. Water to water vapour.
(c) Condensation— The process of conversion of vapour into a liquid. e.g. Water vapour to water.
(d) Freezing— The process of conversion of a liquid into a solid. e.g. Water to ice.
(e) Melting point— The constant temperature at which a solid melts into a liquid. M.P. of ice – 0°C.
(f) Boiling point— The constant temperature at which a liquid starts boiling. B.P. of water – 100°C.
