Answer
(a) $^{6}Li$
3 protons, 3 neutrons, 3 electrons
(b) $^{16}O^+$
8 protons, 8 neutrons, 7 electrons
(c) $^{13}N^{++}$
7 protons, 6 neutrons, 5 electrons
Work Step by Step
(a) $^{6}Li$
A lithium atom has 3 protons and since there are 6 nucleons, the atom must have 3 neutrons. Since the atom is neutral, the atom must have 3 electrons.
(b) $^{16}O^+$
An oxygen ion has 8 protons and since there are 16 nucleons, the ion must have 8 neutrons. Since the ion has a charge of +1, the ion must have 7 electrons.
(c) $^{13}N^{++}$
A nitrogen ion has 7 protons and since there are 13 nucleons, the ion must have 6 neutrons. Since the ion has a charge of +2, the ion must have 5 electrons.
