How does boiling differ from evaporation in terms of state change?

Boiling is a rapid state change from liquid to gas at a specific temperature, unlike evaporation which is gradual.

Boiling and evaporation are both processes that involve the transition from a liquid state to a gas state. However, they occur under different conditions and have different characteristics. Boiling is a rapid process that happens when a liquid reaches a specific temperature, known as its boiling point. At this temperature, the liquid's vapour pressure equals the atmospheric pressure, and bubbles of vapour form directly within the liquid. This is why you see bubbles when water is boiling - it's the water turning into steam.

Evaporation, on the other hand, is a slower process that can occur at any temperature. It happens when molecules at the surface of a liquid gain enough energy to overcome the forces of attraction holding them in the liquid, and escape into the air as gas. This is why a puddle of water can disappear over time, even on a cool day. The rate of evaporation depends on factors such as the surface area of the liquid, the temperature, and the humidity of the air.

In summary, while both boiling and evaporation involve a change from liquid to gas, they are different in their speed, the conditions under which they occur, and the way they happen. Boiling is a rapid, bulk process that happens at a specific temperature, while evaporation is a slower, surface process that can happen at any temperature.