Answer:
Technetium (Tc) and Rhodium (Rh)
Step-by-step 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