Which is the only metal that is liquid at room temperature?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Mercury
Mercury (Hg) is the only metal that is a liquid at ordinary room temperature: it melts at about −39°C and boils only at about 357°C. This is why it was long used in thermometers and barometers.
Why the other options are incorrect
Option (1) Bromine — Incorrect. Bromine is also a liquid at room temperature, but it is a non-metal (a halogen).
Option (3) Tungsten — Incorrect. Tungsten has the highest melting point of all metals, about 3422°C, which is why it is used in bulb filaments.
Option (4) Gallium — Incorrect. Gallium melts at about 30°C, so it is solid at room temperature but melts in the hand.