Read the following passage and answer the questions based on it.

The transition metals are very hard and have low volatility. Their melting and boiling points are high. In any row, the melting points of these metals rise to a maximum at $d^5$ and fall regularly as atomic number increases. The high melting points of these metals are attributed to the involvement of greater number of electrons from (n-1)d in addition to ns electrons in the interatomic metallic bonding.

Which transition metal is liquid at room temperature?

Hg

The correct answer is Option (1) → Hg.

The only transition metal that is liquid at room temperature (approximately 20-25°C) is Mercury (Hg). Let us delve into the details of each metal listed to understand why this is the case.

Analysis of Each Metal

1. Mercury (Hg)

Mercury is unique among metals because it is a liquid at room temperature. The melting point of mercury is about \(-38.83°C\), which means it remains liquid at room temperature. Due to its liquid state, mercury has been historically used in thermometers and barometers.

2. Copper (Cu)

Copper is a solid metal at room temperature. The melting point of copper is about \(1,984°C\). Copper is widely used in electrical wiring and plumbing due to its excellent conductivity.

3. Silver (Ag)

Silver is also a solid metal at room temperature. The melting point of silver is about \(961.8°C\). Silver is known for its high electrical and thermal conductivity and is often used in jewelry and electronics.

4. Gold (Au)

Gold is a solid metal at room temperature. The melting point of gold is about \(1,064°C\). Gold is primarily used in jewelry, electronics, and as an investment in the form of bullion.

Conclusion

The only transition metal that exists as a liquid at room temperature is: Mercury (Hg).