Question

Which of the following statement is incorrect for the isoelectronic species?

• A. Isoelectronic species have the same number of electrons.
• B. Isoelectronic species have different numbers of protons.
• C. In isoelectronic species, the ionic radii decrease with an increase in nuclear charge.
• D. None Of These

Answer 1

The correct option is D

None Of These

The explanation for the correct answer:

(D) None Of These

Isoelectronic species:

• Isoelectronic species refers to two atoms, ions, or molecules that have the same electronic structure and the same number of valence electrons.
• Meaning of isoelectronic is "equal electric" or “equal charge”.
• Isoelectronic chemicals display similar chemical properties.
• Atoms or ions with the same electronic configurations are said to be isoelectronic to each other.
• It can also be said that these species have the same isoelectronicity.
• Some examples of isoelectronic species are;

Isoelectronic Ions/Elements	Electronic Configuration
$\mathrm{He},{\mathrm{Li}}^{+}$	$1{\mathrm{s}}^2$
$\mathrm{He},{\mathrm{Be}}^{2+}$	$1{\mathrm{s}}^2$
$\mathrm{Ne},{\mathrm{F}}^{-}$	$1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^6$
${\mathrm{Na}}^{+},{\mathrm{Mg}}^{2+}$	$1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^6$
$\mathrm{K},{\mathrm{Ca}}^{2+}$	$\left[\mathrm{Ne}\right]4{\mathrm{s}}^1$
$\mathrm{Ar},{\mathrm{S}}^{2-}$	$1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^6$
${\mathrm{S}}^{2-},{\mathrm{P}}^{3-}$	$1{\mathrm{s}}^{2}2{\mathrm{s}}^{2}2{\mathrm{p}}^{6}3{\mathrm{s}}^{2}3{\mathrm{p}}^6$

The explanation for the incorrect answer:

(A) Isoelectronic species have the same number of electrons

• This option is incorrect because isoelectronic species have the same number of electrons.
• This statement is correct.

(B) Isoelectronic species have different numbers of protons

• This option is incorrect because isoelectronic species have different numbers of protons.
• This statement is correct.

(C) In isoelectronic species, the ionic radii decrease with an increase in nuclear charge

• This option is incorrect because, in isoelectronic species, the ionic radii decrease with an increase in nuclear charge.
• This statement is correct.

Hence, the correct option is (D) None Of These.