Based on the compounds of group 15 elements, the correct statement(s) is/are: NF3 is more covalent than BiF3. Bi2O5 is more basic than N2O5. PH3 boils at lower temperature than NH3. The N−N single bond is stronger than the P−P single bond.

The correct options are
A. Bi2O5 is more basic than N2O5.
B. NF3 is more covalent than BiF3.
C. PH3 boils at lower temperature than NH3
(A) Bi2O5 is a metallic oxide, but N2O5 is a non-metallic oxide; therefore, Bi2O5 is basic, but N2O5 is acidic.
(B) In NF3, N and F are non-metals, but in BiF3, Bi is a metal, while F is a non-metal; therefore, NF3 is more covalent than BiF3.
(C) In PH3, hydrogen bonding is absent, but in NH3, hydrogen bonding is present; therefore, PH3 boils at a lower temperature than NH3.
(D) Due to the small size in the N−N single bond, 2p-2p repulsion is more than in the P−P single bond; therefore, the N−N single bond is weaker than the P−P single bond.