Chemistry - Complete Pblock- Question with Solution | TestHub

The melting points are: Boron (B) $\approx 2075^{\circ }C$, Aluminum (Al) $\approx 660^{\circ }C$, Gallium (Ga) $\approx 29.8^{\circ }C$, Carbon (C) $\approx 3500^{\circ }C$ (sublimes). Gallium has the lowest melting point among the given options.

Explanation:

Melting point is the temperature at which a solid changes to a liquid.

Boron (B) is a metalloid with a very high melting point due to its strong covalent network structure.

Aluminum (Al) is a metal with a relatively high melting point.

Gallium (Ga) is a metal known for its unusually low melting point, close to room temperature. This is due to its unique crystal structure, which has weak metallic bonding between some atoms.

Carbon (C) in its solid forms (diamond, graphite) has extremely high melting/sublimation points due to strong covalent bonds.

Comparing the approximate melting points:

B: $2075^{\circ }C$

Al: $660^{\circ }C$

Ga: $29.8^{\circ }C$

C: $\approx 3500^{\circ }C$ (sublimes)

Therefore, Gallium (Ga) has the lowest melting point among the given elements.