Transition Metal Properties in the Periodic Table

Steps:

• Identify positions: A in Group 1 (alkali metal), B in Group 17 (halogen), C in d-block (transition metal), D in Group 14 (metalloid like carbon group).
• Recall high melting point indicates strong metallic bonding, common in transition metals.
• Note variable oxidation states arise from partially filled d-orbitals, unique to d-block elements.
• Match traits to C, as it fits both criteria.

Why C is correct:

• Transition metals exhibit high melting points from delocalized d-electrons strengthening metallic bonds and variable oxidation states per the electron configuration allowing multiple d-electron losses.

Why the others are wrong:

• A: Alkali metals have low melting points and fixed +1 oxidation state due to single valence electron.
• B: Halogens are nonmetals with low melting points and typically -1 oxidation state in compounds.
• D: Group 14 elements like metalloids have moderate melting points but fixed oxidation states (e.g., +4 for carbon).

Final answer: C