The following are isoelectronic ions except

  • A Na\(^+\)
  • B Mg\(^{2+}\)
  • C Si\(^{2+}\)
  • D O\(^{2+}\)
jamb 2019chemistry

The correct answer is C. Si\(^{2+}\)

Two or more ions are said to be isoelectronic if they have the same electronic structure and the same number of valence electrons.

Na\(^+\) = 10 electrons = 2, 8

Mg\(^{2+}\) = 10 electrons = 2,8

O\(^{2-}\) = 10 electrons = 2,8

Si\(^{2+}\) = 12 electrons = 2,8,2

\(\implies\) Si\(^{2+}\) is not isoelectronic with the rest.

Previous question Next question