Two elements in the second transition series (Y through

Cd) have four unpaired electrons in their 3 + ions. What elements

fitthis description?

Technetium (Tc) and Rhodium (Rh)

Explanation:

The two elements in the second transition series (Y through Cd) that have four unpaired electrons in their 3⁺ ions are

Tc [Kr] 4d⁵5s² after losing 3 electron becomes Tc [Kr] 4d⁴ and

Rh [Kr] 4d⁸ 5s¹ after losing 3 electron becomes Rh [Kr] 4d⁶ where Kr is the electronic configuration of Krypton (a noble gas)

so both Technetium (Tc) and Rhodium (Rh) have four unpaired electrons

Technetium and Rhodium

Explanation:

For Technetium, Symbol: Tc

Atomic number: 43

Electron configuration: [Kr] 4d55s2

Atomic mass: 98 u

For Rhodium, Symbol: Rh

Electron configuration: [Kr] 4d85s1

Atomic number: 45

Atomic mass: 102.9055 u