According to molecular orbital theory, the number of unpaired electron(s) in $$O_2^{2 - }$$ is :

The number of hydrogen bonded water molecule(s) associated with stoichiometry CuSO₄.5H₂O is ____________.

The number of species having non-pyramidal shape among the following is ___________.

(A) SO₃

(B) NO$$_3^ - $$

(C) PCl₃

(D) CO$$_3^{2 - }$$

AB₃ is an interhalogen T-shaped molecule. The number of lone pairs of electrons on A is __________. (Integer answer)