In the molecular orbital diagram for the molecular ion, N₂⁺, the number of electrons in the $$\sigma $$_2pz molecular orbital is :

Which of the following is a Lewis acid?

For Na⁺, Mg²⁺, F^- and O^2-; the correct order of increasing ionic radii is :

In graphite and diamond, the percentage of p-characters of the hybrid orbitals in hybridisation are respectively :