III.
6 . Label formal charges and predict which is the most likely resonance structure for N 2 O:
(A)
(B)
(C)
(D)
7 . Draw Lewis structures of the most likely ions of the elements from Na to Ca.
8 . Draw Lewis structures for each of the following:
(A) nitrate ion ([NO 3 ]–)
(B) phosphoric acid (H 3 PO 4 )
(C) aluminum chloride (AlCl 3 )
(D) sodium phosphate (Na 3 PO 4 )
9 . A hydride is a compound containing hydride ion, H–. Predict two elements whose hydrides
would contain incomplete octets.
10 . Which of the following sets of molecules contains only nonpolar species?
(A) BH 3 , NH 3 , AlH 3
(B) NO 2 , CO 2 , ClO 2
(C) HCl, HNO 2 , HClO 3
(D) BH 3 , H 2 S, BCl 3
(E) BeH 2 , BH 3 , CH 4