As the atomic number increases, the ionisation enthalpy _________ (in a period).

Which elements occupy the maxima of ionisation potential curve?

The first ionisation enthalpies in electron volts of nitrogen and oxygen atoms are respectively given by:
(i) 14.6, 13.6            
(ii) 13.6, 14.6
(iii) 13.6, 13.6          
(iv) 14.6, 14.6

Al atom loses electrons successively to form Al⁺, Al²⁺ and Al³⁺ ions. Which step will have highest ionsiation enthalpy?

Arrange the following in decreasing negative electron gain enthalpy: B, C, N, O.

What is the electron gain enthalpy of neon?

The size of isoelectronic species: F^-, Ne and Na⁺ is affected by:
(a) nuclear charge (Z)
(b) valence principal quantum number (n)
(c) electron-electron interaction in the outer orbitals.
(d) none of the factors because their size in the same.

From the electronic configuration of the elements A, B and C given below:

(i) Which one has least negative electron gain enthalpy and
(ii) Which one has highest ionisation enthalpy value?

Are the oxidation state and covalency of Al in  same?