Video Transcript
Which of the following energy level
diagrams corresponds to the least reactive atom?
We’ve been given five answer
choices labeled from (A) to (E). Energy levels are distances from
the nucleus that describe the location of electrons. The first four energy levels are
called K, L, M, and N, where K is the closest energy level to the nucleus. Electrons fill this energy level
first. They then fill energy level L.
All of the answer choices have two
electrons in K and eight in L. The difference lies in the number
of electrons in energy level M, their outer energy level. Elements tend to be chemically
active if they have fewer than eight electrons in their outer energy level. So the atoms in (A), (B), (D), and
(E) are likely to be chemically active. However, elements tend to be
chemically stable and inert if they have eight electrons in their outer energy
level. Thus, it’s likely that atom (C) is
inert. Therefore, the energy level diagram
which corresponds to the least reactive atom is answer choice (C).
