Question

Why does water evaporate before its boiling point $?$

Answer 1

Hint : Evaporation is the process by which water changes from a liquid to a gas or vapor. Evaporation is the primary pathway that water moves from the liquid state back into the water cycle as atmospheric water vapor.

Complete Step By Step Answer:
$-$Evaporation happens when a liquid substance becomes a gas. When water is heated, it evaporates. The molecules move and vibrate so quickly that they escape into the atmosphere as molecules of water vapor.
$-$Evaporation can take place at temperatures below boiling point since the molecules in the liquid have different energies. This process lowers the energy of the remaining molecules and is the source of cooling in evaporating liquids.
$-$The boiling point of water is $100\deg C$at$1atm$. This is the temperature that liquid is in equilibrium with its gas phase.
Additional information:
Factors that affects evaporation:
Pressure$=$ Evaporation happens faster if there is less exertion on the surface keeping the molecules from launching themselves.
Surface area$=$ A substance that has a larger surface area will evaporate faster, as there are more surface molecules per unit of volume that are potentially able to escape.
Temperature$=$ The higher the temperature of the substance the greater the kinetic energy of the molecules at its surface and therefore the faster the rate of their evaporation.

Note :
Evaporation is an endothermic process, in that heat is absorbed during evaporation. The particles absorb more heat energy making them vibrate faster. Molecules that are evaporating are absorbing heat. Remember, endo means to enter while thermic means heat.