Change of State of Matter

→ The phenomenon of change from one state of matter to another, and then back to the original state is called the interconversion of states of matter.

→ Matter Can Change its State. Water can exist in three states of matter:

• Solid as ice

• Liquid as water

• Gas as water vapour

Effect of Temperature

→ On increasing the temperature of solids, the kinetic energy of the particles increases which overcomes the forces of attraction between the particles thereby solid melts and is converted into liquid.

→ The temperature at which a solid melts to become a liquid at the atmospheric pressure is called its

melting point.

The melting point of ice is 273.16 K.

The process of melting, that is, change of solid state into liquid state is also known as fusion.