Question

Two elements in the second transition series (y through cd ) have three unpaired electrons in their 3+ ions. what elements fit this description?

Answer 1

Molybdenum and Rhodium, I believe. All of the elements in these 2 groups follow unusual orbital filling rules.

Hope this helped!

Answer 2

Answer: The elements that have 3 unpaired electrons in their +3 oxidation states are Molybdenum and Palladium.

Explanation: The elements in the second transition series are:

Yttrium (Y), Zirconium (Zr), Niobium (Nb), Molybdenum (Mo), Technetium (Tc), Ruthenium (Ru), Rhodium (Rh), Palladium (Pd), Silver (Ag) and Cadmium (Cd).

The electronic configuration of these elements are:

$Y=[Kr]5s^24d^1$             ;      $Y^{3+}=[Kr]$

$Zr=[Kr]5s^24d^2$           ;      $Zr^{3+}=[Kr]4d^1$

$Nb=[Kr]5s^14d^4$           ;      $Nb^{3+}=[Kr]4d^2$

$Mo=[Kr]5s^14d^5$           ;     $Mo^{3+}=[Kr]4d^3$

$Tc=[Kr]5s^14d^6$            ;     $Tc^{3+}=[Kr]4ds^4$

$Ru=[Kr]5s^14d^7$            ;     $Ru^{3+}=[Kr]4d^5$

$Rh=[Kr]5s^14d^8$            ;     $Rh^{3+}=[Kr]4d^6$

$Pd=[Kr]5s^04d^{10}$          ;     $Pd^{3+}=[Kr]4d^7$

$Ag=[Kr]5s^14d^{10}$           ;     $Ag^{3+}=[Kr]4d^8$

$Cd=[Kr]5s^24d^{10}$          ;     $Cd^{3+}=[Kr]4d^9$

From the above configurations of the elements in their +3 ionic state, the elements having 3 unpaired electrons are Molybdenum and Palladium.