Mercury has 80 protons, which is also the element's atomic number. Mercury has an atomic weight of 200.59 amu, and its chemical symbol is Hg.
Protons are particles that carry a positive charge. They exist in the nucleus of an atom along with neutrons, which have no charge. In addition to 80 protons, mercury has 80 electrons and 121 neutrons in its stable state. The electrons have a negative charge, and they are located in orbits around the nucleus.
Mercury has been known since antiquity. It is a silver liquid metal element that was named after the planet Mercury. Mercury is mined from cinnabar ore as it is rarely found free in nature.