An atom of which element possesses electrons in only the first and second energy levels? (The number in parentheses indicates the number of electrons in an atom of that element.)
A)sodium (11)
B)magnesium (12)
C)chlorine (17)
D)neon (10)
E)argon (18)

Question

Quizplus · Accepted Answer

A neutral atom of neon has 10 electrons, distributed across the first two energy levels (2 in the first and 8 in the second). Sodium, magnesium, and chlorine all have electrons distributed across the third energy level, while argon has electrons distributed across the third and fourth energy levels.

An Atom of Which Element Possesses Electrons in Only the First