Which of the following ions has an electron configuration different from the other?
- A.17CI–
- B.8O2-
- C.12Mg2+
- D.13AI3+
Correct Answer: Option A
Explanation
(_{17})Cl(^-) = 18 electrons = 2, 8, 8
(_{12})Mg(^{2+}), (_{8})O(^{2-}) and (_{13})Al(^{3+}) all have 10 electrons = 2, 8.