Boiling is the process in which a liquid changes to a vapor when it is heated to its boiling point. At the boiling point, the vapor pressure of the liquid equals the pressure exerted on the liquid by the surrounding atmosphere. This is why bubbles form and rise to the surface of the liquid when it boils.
The boiling point of a substance is the temperature at which the vapor pressure of the liquid is equal to the external pressure acting on the surface of the liquid. This is why the boiling point of a liquid varies with changes in atmospheric pressure. For example, water boils at a lower temperature at higher altitudes where the atmospheric pressure is lower.
Understanding the process of boiling is crucial in various fields, from cooking to industrial processes. Mastery of this topic will also help in comprehending phase changes and the behavior of substances under different conditions.