Most metals around us are solid iron, copper, aluminium and gold all hold their shape at room temperature. But there is one remarkable exception: mercury.

Mercury is a metal, yet it remains liquid at room temperature because its melting point is only −38.83°C.

So, what makes mercury different? The two electrons in its 6s orbital are happily paired up with each other and are reluctant to be shared among neighbouring atoms.

This gives mercury its distinctive silvery, flowing appearance and makes it one of the most unusual elements on the periodic table.

A metal that flows like a liquid: mercury is a fascinating reminder that metals do not always behave the way we expect.