State one difference between a gas and a vapour.

Why does the temperature of a substance remain constant during its melting point or boiling point?

$(a)$ State one similarity and one difference between evaporation and boiling.
$(b)$ Account for the following:
$(i)$ We wear cotton clothes in summer.
$(ii)$ $A$ wet handkerchief is placed on the forehead of a person suffering from high fever.
$(iii)$ Wet clothes dry slowly during the rainy season.

The boiling points of diethyl ether, acetone, and $n-$butyl alcohol are $35\,^\circ\text{C}$, $56\,^\circ\text{C}$, and $118\,^\circ\text{C}$ respectively. Which one of the following correctly represents their boiling points in the Kelvin scale?

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

Arrange honey, water, and hydrogen in descending order on the basis of the following properties exhibited by them:
$(a)$ Kinetic energy
$(b)$ Density