Question

Which elements/ions have same number of unpaired electrons?
(1) $Fe ^{3+}$
(2) $Cr$
(3) $Cu ^{+}$
(4) $V $

• A. 1, 2 and 3 are correct
• B. 1 and 2 are correct
• C. 2 and 4 are correct
• D. 1 and 3 are correct

Answer 1

Answer: (B)

$Fe ^{3+}( Z =26):[ Ar ] 3 d^{5}, 4 s^{0}: 5$ unpaired electrons
$Cr ( Z =24):[ Ar ] 3 d^{5} 4 s^{1}: 5$ unpaired electrons