What is Mercury?

Mercury was originated in the 6th-century alchemy. It was named after the planet Mercury. The symbol of Mercury is Hg.

The atomic number is 80. Mercury's state of matter is liquid and is classified as a transition metal or post-transitional. It is the only metal that is liquid at room temperature. 

It's atomic mass is 200.592. It has 121 neutrons and 80 of each protons and electrons. 

Mercury's Chemical Behavior

Mercury reacts with atmospheric hydrogen sulfide. It does not react with most acids but can dissolve into sulfate, nitrate and chloride if it is combined with oxidizing acids such as sulfuric acid and nitric acid. 

It can dissolve metals such as gold and silver to form amalgams (an alloy of mercury with another metal). Mercury reacts with solid sulfur flakes and can be used in Mercury spill kits to absorb mercury. 

What is Mercury's Purpose?

Mercury is used in many things that we use or apply to our daily life, such as thermometers and florescent lights. It was used mainly in industrial chemicals and electric applications. Although, due to health and safety regulations it has been replaced by a safer and less toxic alloy called Galinstan. 

It is used in medicines such as vaccines as a preservative and also used in dental practices to fill cavities. Mercury has declined in many medical  medicines but still are found in over the counter drugs and vaccines. The FDA has "inadequate data to establish general recognition of the safety and effectiveness" of Mercury in these products. 

Mercury can also be found in fish. Tuna and albacore tuna rank high in Mercury levels. 

Cosmetics such as mascara have also been known to contain levels of Mercury. 

https://www.britannica.com/science/mercury-chemical-element

https://en.wikipedia.org/wiki/Mercury_(element)