(N/A) Boiling point: The temperature at which the vapour pressure of a liquid becomes equal to the external atmospheric pressure (typically $1 \text{ atm}$) is called the boiling point of the liquid.
Factors affecting boiling point:
$1$. Nature of liquid: Each liquid has a characteristic boiling point. If the intermolecular forces of attraction in a liquid are weak,the molecules can easily escape into the vapour phase,resulting in higher vapour pressure and a lower boiling point. Such liquids are more volatile. For example,the boiling points of water,ethanol,and ether are $100^{\circ}C$,$78^{\circ}C$,and $34^{\circ}C$ respectively.
$2$. External pressure: The boiling point of a liquid depends on the external pressure applied to its surface. If the atmospheric pressure is lower,the liquid reaches its boiling point at a lower temperature. For example,on high mountains,atmospheric pressure is lower,so water boils at a temperature lower than $100^{\circ}C$. Conversely,in a pressure cooker,the pressure is increased,which raises the boiling point of water,allowing food to cook faster.