Inter-conversion of the States of Matter
Depending on the conditions of temperature and pressure, matter can exist in any of the three main states i.e., solid, liquid or gas. Matter can be inter-converted from one state to the other by the addition or removal of heat energy. All the three states of matter are inter-convertible.
For example, when water is cooled to 0oC, it transforms into ice (solid). On heating, at 100oC, it begins to boil and gets converted into vapour (gas). On cooling, water vapour gradually reconverts back into water (liquid).
