Each of the following species will be encountered at some point in this text. They all have the same number of electrons binding the same number of atoms and the same arrangement of bonds; they are isoelectronic. Specify which atoms, if any, bear a formal charge in the Lewis structure given and the net charge for each species.

(a) : N ≡ N:
(b) : C ≡ N:
(c) : C ≡ C:
(d) : N ≡ O:
(e) : C ≡ O: