What is the value of electron gain enthalpy of Na+ if IE1 of Na = 5.1 eV ?

Values of first four ionization potential of an elements are 68, 370, 400, 485. It belongs to

(A), (B) and (C) are elements in the second short period. Oxide of (A) is ionic, that of (B) is amph

The basic character of MgO, SrO, K₂O and NiO increases in the order -

Arrange into the order of increasing basicity (NO₂, K₂O, ZnO) -

Arrange the following hydrides in their increasing acid strength [CH₄, H₂S, PH₃ and SiH₄] -