Which of the following pairs show reverse properties on moving along a period from left to right and from top to down in a group?

The cause of the diagonal relationship is:

The electronic configurations of $4$ atoms are given below:
$P = [Ne] \, 3s^2 3p^3$
$Q = [Ar] \, 3d^{10} 4s^2 4p^3$
$R = [He] \, 2s^2 2p^5$
$S = [Ne] \, 3s^1$
Which of the following statements is incorrect?

If the period number and group number of any representative element are the same,then which of the following statements is incorrect regarding such type of element in its ground state? (Period number and group number are according to the modern form of the periodic table)

Nitrogen has positive electron gain enthalpy whereas oxygen has negative. However,oxygen has lower ionisation enthalpy than nitrogen. Explain.

Which of the following properties does not depend on periodicity?