Question

Which of the following does not represent the correct order of the properties indicated?

• A. $N{i}^{2+}>C{r}^{2+}>F{e}^{2+}>M{n}^{2+}(size)$
• B. $Sc>Ti>Cr>Mn(size)$
• C. $N{i}^{2+}<C{o}^{2+}<F{e}^{2+}<M{n}^{2+}$ (unpaired electron)
• D. Fe${}^{2+}>C{o}^{2+}>N{i}^{2+}>C{u}^{2+}$(unpaired electron)

Answer 1

Answer: (A)

In a period on moving from left to right ionic radii
decreases. So, the order of cationic radii is
Cr${}^{2+}>M{n}^{2+}>F{e}^{2+}>N{i}^{2+}$
In Sc > Ti > Cr > Mn (correct order of atomic radii)
$InM{n}^{2+}>N{i}^{2+}<C{0}^{2+}<F{e}^{2+}$
$\downarrow \downarrow \downarrow \downarrow$
$FiveTwoThreeFour$
$unpairedunpairedunpairedunpaired$
$electronselectronselectronselectrons$
$InF{e}^{2+}>C{o}^{2+}>N{i}^{2+}>C{u}^{2+}$
${}_4^{\downarrow }{}_3^{\downarrow }{}_2^{\downarrow }{}_1^{\downarrow }$
Number of unpaired electrons