How many of the following elements can form compounds with an expanded octet? P Kr As B
A) 0
B) 1
C) 2
D) 3
E) 4

Question

Quizplus · Accepted Answer

Out of the given elements, only P, Kr, As, and B can form compounds. 
Kr is a noble gas and already has a filled octet, so it cannot form compounds with an expanded octet. 
B only has 3 valence electrons, so it cannot form compounds with an expanded octet. 
However, both P and As can form compounds with an expanded octet in certain situations. Therefore, the answer is 3.

How Many of the Following Elements Can Form Compounds with an Expanded