Mercury

liquid metal · quicksilver · chemistry

Liquid at room temperature. While almost all metals are hard and solid, mercury is the only one that flows like a liquid when you're just sitting around at normal temperature. This makes it super unique and special among all the metals on Earth.

Freezes and boils easily. Mercury has the lowest freezing point and lowest boiling point of any metal, which means it can change from solid to liquid to gas with smaller temperature changes than other metals. This narrow liquid range is one of the reasons it's so unusual.

Shiny silvery appearance. Mercury looks like a beautiful, smooth, reflective liquid silver, which is why it earned the nickname 'quicksilver' long ago. It bounces around into little spheres when you pour it because of how the liquid holds together.

Super heavy metal. Even though mercury is liquid, it's actually very dense and heavy for its size, making it denser than most other metals including iron. A small jar of mercury can weigh as much as you'd expect a much larger container to weigh.

Used in thermometers. Because mercury expands and shrinks very predictably with temperature changes, it was used for centuries in thermometers to measure heat. Scientists and doctors would watch the mercury rise or fall to know how hot something was.