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?

Question

Quizplus · Accepted Answer

An atom is unstable or reactive when its outermost energy level is not full. In this case, choice D has only 1 electron in the third/final energy level, which means it has an incomplete outermost shell and is likely to react with other atoms to gain stability. Therefore, D is the most unstable/reactive atom among the choices given.

The Numbers Listed Represent the Number of Electrons in the First,second,and