Arrange the following metals in decreasing order of their melting poi…

The correct answer is Option (4) → (C), (A), (D), (B)

Transition metals have high melting points because of strong metallic bonding, in which the (n−1)d electrons take part along with the ns electrons. The melting points follow two trends:

• Across a series: the melting point rises to a maximum near the middle (d⁵), where the number of unpaired d electrons is greatest, and then falls. Manganese is an exception with an unusually low melting point, and copper (d¹⁰) at the end of the series is low.

• Down a group: the 4d and 5d metals have much higher melting points than the 3d metals, because their larger d orbitals form stronger metallic bonds.

So the melting points decrease as:

    5d (group 6) > 4d (group 6) > 3d (group 7) > 3d (group 11)
    W > Mo > Mn > Cu

Matching the given metals:

• (C) Tungsten: 5d, m.p. about 3680 K (highest of all metals)

• (A) Molybdenum: 4d, m.p. about 2890 K

• (D) Manganese: 3d, m.p. about 1520 K

• (B) Copper: 3d, filled d subshell, m.p. about 1360 K

Shortcut: Tungsten (C) has the highest melting point of any metal and copper (B) the lowest here. Options (3) and (4) both start with (C) and end with (B). Molybdenum, a 4d metal, melts higher than manganese, so (A) comes before (D), and only Option (4) remains.

NCERT (2026-27 edition):
Physical Properties – …