Question

Among the following the incorrect statement about transition metals is

• A. Cr, Mo and W have high melting points
• B. With increase in number of unpaired electrons melting point increases
• C. Mn³⁺ is more stable than Mn²⁺
• D. They show variable oxidation states

Answer 1

The Correct Option is B

The correct option is: (B): With increase in number of unpaired electrons melting point increases.

The atomic radii of transition metals demonstrate a rapid expansion in correspondence to a rise in atomic number due to inadequate shielding provided by the (n−1)d electrons. a) Although the electrons in the ns orbital have the first egress, they encounter filling prior to the (n−1)d orbitals. b) Owing to the deficient shielding of d electrons, an escalation in atomic number leads to an augmentation in effective nuclear charge (zeff) and a subsequent contraction in atomic radii. c) Elements in the second and third transition series exhibit nearly identical sizes because of the lanthanide contraction. d) This phenomenon stems from the weakened shielding impact generated by the 4f electrons.