IMAT 2016 Q44 [Electronic Structure]

Which of these particles have the same electronic structure?

  1. _{12}Mg^{2+}
  2. _{10}Ne
  3. _{16}S^{2-}
  4. _9Fe^-
  5. _3Li^+

A. 1, 2 and 5 only
B. 2, 4 and 5 only
C. 1, 2 and 3 only
D. 3, 4 and 5 only
E. 1, 2 and 4 only

The electronic structure for each should be as follows:

  1. _{12}Mg^{2+} : 2,8
  2. _{10}Ne : 2,8
  3. _{16}S^{2-} : 2,8,8
  4. _9Fe^- : 2,8
  5. _3Li^+ : 2

Our answer should therefore be 1, 2 and 4 as we can see. That makes it option E.