Answer
Please see the work below.
Work Step by Step
The ionization enthalpy or first ionization enthalpy is the energy required to remove the most loosely bound electron from an isolated gaseous neutral atom in the ground state.
Ionization enthalpy is measured in a gaseous state because there are weaker interatomic interactions in a gaseous state than in other states.
The second ionization is the energy required to remove the most loosely bound electron from a gaseous unipositive ion. This generally requires more energy than removing the first electron.
