The numbers listed represent the number of electrons in the first, second, and third energy levels, respectively. On this basis, which of the following is an unstable or reactive atom?
A) 2, 8
B) 2
C) 2, 8, 1
D) 2, 8, 8

Question

Quizplus · Accepted Answer

An atom is unstable or reactive if its outermost energy level is not full. In option C, the third energy level has only 1 electron, making it reactive.

The Numbers Listed Represent the Number of Electrons in the First