Chemical Thermodynamics — Chemistry STD 12 Science — Question

Enthalpy of atomization:
The enthalpy change accompanying the dissociation of all the molecules in one mole of gas phase substance into gaseous atoms is called enthalpy of atomisation.
Enthalpy of vaporization:
The enthalpy change that accompanies the vaporization of one mole of liquid without changing its temperature at constant pressure is called enthalpy of vaporization.