With which name is the phenomenon of changing of a liquid into its vapours at a temperature below its boiling point known?

What happens when you open a bottle of perfume?

$(a)$ Define boiling point.
$(b)$ Express the boiling point of water in Celsius as well as Kelvin scale.
$(c)$ $A$ diver is able to cut through water in a swimming pool. Which property of matter does this observation show?

When suffering from a fever,which will lower your body temperature more effectively: ice or ice-cold water? Why?

What is the effect of a change in pressure on the physical state of matter? Explain with an example of a gas.

What happens to the heat energy that is supplied to a solid once it starts melting?