Video Transcript
Which of the following letters is
not used to represent an energy level? (A) I, (B) K, (C) L, (D) M, or (E)
N.
Energy levels are regions around
the nucleus in which electrons move according to their energies. The first energy level is referred
to as energy level K, and it can hold a maximum of two electrons. Electrons fill energy level K
first. The second energy level is L, and
it can hold a maximum of eight electrons. The third energy level is energy
level M. It holds a maximum of 18
electrons. N is the fourth energy level. It holds a maximum of 32
electrons.
Therefore, K, L, M, and N are all
letters used to represent energy levels. Atoms can contain more energy
levels beyond these four. But we can already see that four of
the five answer choices do represent an energy level.
Thus, of the letters given in the
answer choices, the one that’s not used to represent an energy level is I, or answer
choice (A).
