Question

Metals are generally solid. Which of the following metals is in the liquid state at room temperature?

• A. Mercury
• B. Silver
• C. Aluminium
• D. Sodium

Answer 1

The correct option is A

Mercury

The explanation for correct answer:-

Option (A) Mercury

• Mercury is reluctant at sharing electrons, unlike other metals which share their valence electrons and form bonds or ions.
• Electrons in mercury atoms are bound tighter than normal to the nucleus and electrons move so fast and close to the nucleus that they exhibit relativistic effects as if they were heavier than slower moving electrons.
• Therefore very little heat is needed to overcome the weak bond between mercury atoms due to the behaviour of the valence electrons mercury has a low melting point and hence mercury is liquid at room temperature.

The explanation for incorrect answer:-

Option (B) Silver

• Silver is solid at room temperature, and can only be liquid if heated.
• The melting point of Silver is $961.8°\mathrm{C}$.
• Hence it is the incorrect option.

Option (C) Aluminium

• The melting point of Aluminium is $660.3°\mathrm{C}$.
• Aluminium is solid at room temperature.
• As a result it can only be liquid when it is heated.
• Hence it is the incorrect option.

Option (D) Sodium

• Sodium is a very soft and reactive metal.
• It exists as a solid at room temperature and therefore can be liquid only when it is heated.
• The melting point of Sodium is $97.8°\mathrm{C}$.

Therefore, Option (A) is correct answer.