The molecule AX₃,in which A is the central atom,is polar and obeys the octet rule; therefore, A)A has two lone pairs. B)A has one lone pair. C)A has no lone pairs. D)A has four bonding pairs. E)A has three lone pairs.

Question

Quizplus · Accepted Answer

According to the octet rule, A should have 8 valence electrons in its outer shell. The molecule has two S atoms bonded to A, each contributing 2 electrons, and two B atoms bonded to A, each contributing 3 electrons. This adds up to 16 electrons, leaving A with only 2 valence electrons. Since the molecule is polar, A must have a lone pair to create an uneven distribution of charge. Therefore, the best choice is B, A has one lone pair.

The Molecule AX3,in Which a Is the Central Atom,is Polar

The Molecule AX₃,in Which a Is the Central Atom,is Polar