Question

Ionic radii of

• A. $Ti^{4+}$
• B. $^{35}_{}CI^- < \, ^{37}_{}CI^-$
• C. $K^+ > CI^-$
• D. $P^{3+} > P^{5+}$

Answer 1

Answer: (D)

$P^{3+} > P^{5+}$

Answer 2

(a) $Ti^{4+} > Mn^{7+}$ is the correct order of size due to lower positive charge on $Ti^{4+}$.
(b) $^{35}_{}CI^- < \, ^{37}_{}CI^-$ : Isotopes with same charge have same size because isotopes differ in compositions of nuclei which
do not affect the atomic/ionic radius.
(c) $K^+ < Cl^-$ is the correct order. Among isoelectronic species, anion has greater size than cation.
(d) $P^{3+} > P^{5+}$ is the correct order. For the same elements, lower the positive charge, larger the ions