Mercury holds the 80th spot on the Periodic Table. It has 80 protons, 80 electrons, and 121 neutrons in a neutral atom. It is in the 6th period, and the 12th group. A neutral atom has an atomic weight of 200.59 AMU. It is a silver color, and it is metallic.
Mercury is the only common metal liquid at room temperature, and it is the heaviest elemental liquid. It rarely occurs freely in nature, but can be found in cinnabar ore, in Italy and Spain. It doesn't conduct heat well, but it is a fair conductor of electricity.
No one knows where, or when Mercury was discovered. All we know is that it was discovered in ancient times. The atomic symbol, Hg, comes from the Latin word "hydrargyrum" which means "liquid silver". It is named after the planet Mercury.
Mercury was known to ancient Chinese and Hindus before 2000 BC, and was found in tubes in Egyptian tombs dating from 1500 BC.
The Greeks used mercury in ointments and the Romans used it in cosmetics, but since it is a poison, many died from that.
Mercury is one of the elements, which has an alchemic symbol, which is very similar to the scientific symbol for a female, but with a semicircle at the top. This means it was used in ancient times to try and find the elixir of life, and a method to turn base metals to gold.
When John Dalton was working with atoms, he created his own symbol for Mercury, which is a circle, with 8 lines sticking inward toward the center.