Multiple choice Which of the following are isoelectronic species? A: Al+3 B: Cl- C: Mg+2 D: O-2 A, B and C B, C and D A, C and D A, B and D A, B, C and D Reveal answer Fill a bubble to check yourself C Correct answer Explanation Yes, .Al+3, Mg+2, and O-2 are isoelectronic species as they all have same number of electrons (10 electrons).