Arrange of the following in :
Increasing order of ionic size:
N^3-, Na⁺, F^-, O^2-, Mg²⁺

Arrange of the following in :
Increasing order of basic character
MgO, SrO, K₂O, NiO, Cs₂O

The linear structure is assumed by :

Arrange the following :

Increasing strength of hydrogen bonding (X-H-X):

O, S, F, Cl, N