Final answer:
True, Nitrogen has a higher ionization enthalpy than Oxygen due to its half-filled p-orbitals. Isoelectronic species have the same number of electrons. Chlorine has a higher negative electron gain enthalpy than Fluorine, and it is false that the second ionization enthalpy of Na is more than that of Mg.
Step-by-step explanation:
The statement that the ionization enthalpy of Nitrogen is greater than that of Oxygen is true. Nitrogen atom has half-filled p-orbitals which make it more stable, hence it requires more energy to remove an electron from it than from Oxygen, which has one p-orbital with paired electrons.
Isoelectronic species are atoms and ions that have the same electron configuration, meaning they have the same number of electrons (“a” is correct). The number of protons is different, which affects their chemical properties and ionic sizes.
The statement that Chlorine has higher negative electron gain enthalpy than Fluorine is also true. While both elements release energy when gaining an electron, Chlorine releases more energy due to its electron affinities, making the process more exothermic.
Regarding the ionization enthalpies for Sodium (Na) and Magnesium (Mg), the assertion that Na's first ionization enthalpy is less than that of Mg is true. Sodium's second ionization enthalpy is indeed more than that of Magnesium, which is false. This is because, after removing the first electron, the second ionization involves removing an electron from a noble gas configuration in Na, which requires significantly more energy.