Question

if an atom has just three electrons, those electrons will be located in energy level(s):
a i and ii
b i only
c i or ii
d i, ii and iii

Explanation:

To determine the energy levels of three electrons, we use the electron - filling rules. The first energy level (I) can hold a maximum of 2 electrons (2n², where n = 1: 2×1²=2). The second energy level (II) starts filling after the first is partially filled. For an atom with 3 electrons, the first energy level (I) will have 2 electrons, and the remaining 1 electron will go to the second energy level (II). So the electrons are in energy levels I and II.

Answer:

a. I and II