Which of the following would have to gain two electrons in order to achieve a noble gas electron configuration?
O Sr Na Se Br
A)Br
B)Sr
C)Na
D)O, Se
E)Sr, O, Se

Question

Quizplus · Accepted Answer

The noble gas electron configuration for Oxygen (O) is [He] 2s2 2p4 and for Selenium (Se) is [Ar] 3d10 4s2 4p4. Both of these elements need to gain two electrons in order to achieve stability and have a noble gas electron configuration. Therefore, the correct choice is D, which includes both O and Se.

Which of the Following Would Have to Gain Two Electrons