Why Is Mercury a Liquid?

Question: Why Is Mercury a Liquid?

Answer: Mercury is the only metal that is a liquid at normal temperatures and pressure. What makes mercury so special? Basically, it's because mercury is bad at sharing... electrons, that is.

Most metal atoms readily share valence electrons with other atoms. The electrons in a mercury atom are bound more tightly than usual to the nucleus. In fact, the s electrons are moving so fast and close to the nucleus they exhibit relativistic effects, behaving as if they were more massive than slower-moving electrons.

It takes very little heat to overcome the weak binding between mercury atoms. Because of the behavior of the valence electrons, mercury has a low melting point, is a poor electrical and thermal conductor and doesn't form diatomic mercury molecules in the gas phase.

Liquid Elements | Mercury Facts