Verified Solution • 2025–26 Session moderate

QJEEM23Ch3d94: JEE Main 2023 Chemistry - Class 11 JEEM23Ch3d94 Solution: Which one of the following sets of ions represents a collection …

Which one of the following sets of ions represents a collection of isoelectronic species?

(Given : Atomic Number : F:9,Cl:17,Na=11,Mg=12,Al=13,K=19,Ca=20,Sc=21\mathrm{F:9,Cl:17,Na=11,Mg=12,Al=13,K=19,Ca=20,Sc=21} )

Multiple Choice Options

  • A K+,Cl−,Ca2+,Sc3+\mathrm{K}^{+}, \mathrm{Cl}^{-}, \mathrm{Ca}^{2+}, \mathrm{Sc}^{3+}
  • B N3−,O2−,F−,S2−\mathrm{N}^{3-}, \mathrm{O}^{2-}, \mathrm{F}^{-}, \mathrm{S}^{2-}
  • C Ba2+,Sr2+,K+,Ca2+\mathrm{Ba}^{2+}, \mathrm{Sr}^{2+}, \mathrm{K}^{+}, \mathrm{Ca}^{2+}
  • D Li+,Na+,Mg2+,Ca2+\mathrm{Li}^{+}, \mathrm{Na}^{+}, \mathrm{Mg}^{2+}, \mathrm{Ca}^{2+}

Step-by-Step Verified Solution

Isoelectronic species have same number of electrons.

K+,Cl−,Ca2+,Sc3+\mathrm{K}^{+}, \mathrm{Cl}^{-}, \mathrm{Ca}^{2+}, \mathrm{Sc}^{3+} all have 18 electrons, hence these are isoelectronic.

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