Question

Which of the following represents the correct electron distribution in magnesium ion?

• A. 2, 8
• B. 2, 8, 1
  
• C. 2, 8, 2
  
• D. 2, 8, 3

Answer 1

The correct option is A

2, 8

When magnesium loses two of its electrons, it becomes the M$g^{2+}$ cation, which implies that the total number of electrons will decrease by 2. As a result, the electron configuration of the M$g^{2+}$ cation must account for a total of 10 electrons.

M$g^{2+}$: 1$s^2$2$s^2$2$p^6$