Question

Determine the only possible 2 ion for which the following two conditions are both satisfied: The net ionic charge is one-tenth the nuclear charge. The number of neutrons is four more than the number of electrons. Express your answer as an ion and as an isotope separated by a comma.

Answer 1

Explanation:

The answer is the Calcium ion. It satisfies the conditions of the question.

Condition 1

The net ionic charge is one-tenth the nuclear charge.

In the Calcium ion,  Ca²⁺. The nuclear charge in this ion is 20. The net ionic charge is 2.

2 / 20 = 1 / 10. So the net ionic charge is indeed one tenth of the nuclear charge.

Condition 2

The number of neutrons is four more than the number of electrons.

Mass Number of Ca²⁺ = 44

Atomic Number = 20

Neutrons =  Mass Number - Atomic Number = 44 -20 = 24

Number of electrons = 20 - 2 = 18

Since Number of Neutrons = 22, Number of electrons = 18. This condition also holds.

As an ion and as an isotope = Ca²⁺, Ca - 42