CBSE (Science) Class 11CBSE
Share

# Which of the Following Are Isoelectronic Species I.E., Those Having the Same Number of Electrons? - CBSE (Science) Class 11 - Chemistry

#### Question

Which of the following are isoelectronic species i.e., those having the same number of electrons?

Na+, K+, Mg2+, Ca2+, S2–, Ar

#### Solution

Isoelectronic species have the same number of electrons.

Number of electrons in sodium (Na) = 11

Number of electrons in (Na+) = 10

A positive charge denotes the loss of an electron.

Similarly,

Number of electrons in K+ = 18

Number of electrons in Mg2+ = 10

Number of electrons in Ca2+ = 18

A negative charge denotes the gain of an electron by a species.

Number of electrons in sulphur (S) = 16

∴ Number of electrons in S2- = 18

Number of electrons in argon (Ar) = 18

Hence, the following are isoelectronic species:

1) Na+ and Mg2+ (10 electrons each)

2) K+, Ca2+, S2– and Ar (18 electrons each)

Is there an error in this question or solution?

#### Video TutorialsVIEW ALL 

Solution Which of the Following Are Isoelectronic Species I.E., Those Having the Same Number of Electrons? Concept: Atomic Number.
S