Mercury was made known to the ancient Chinese and Hindu races and was also found in Egyptian tombs dating back to 1500 BCE. In Ancient Chinese culture, mercury was thought to make life longer, heal injuries and maintain good health. The first Chinese emperor Qin Shi Huang Di took mercury pills to obtain eternal life, but went insane then died. Another example of mercury poisoning is the Mad Hatter from Alice in Wonderland. Qin Shi Huang Di

Mercury was once used in hat making, where the skin of the animal was soaked in mercuric nitrate, which separated the fur from the pelt. Mercury was a very common metal in alchemy. It was believed by many to be the ‘First Matter’ from which all metals were formed. The metals could be altered by changing the quality and quantity and quality of the sulfur within the mercury.

Mercury was named after both the planet Mercury and the Ancient Roman god, also Mercury, who was known for his speed and mobility. This god was also known in Greek mythology as Hermes, the messenger between gods and humans. Mercury is the only metal to be commonly be known by its alchemical and planetary name.

Mercury has a few interesting physical properties. It is the only metal to be a liquid at room temperature, which is 298K or 25°C. It is also the heaviest known elemental liquid. Mercury is silvery- white in colour. It is a very poisonous element, prolonged exposure can cause disruption of the nervous system, damage to brain functions, DNA damage and chromosomal damage, allergic reactions, resulting in skin rashes, tiredness and headaches and negative reproductive effects, such as sperm damage, birth defects and miscarriages. Poisoning can also result in death. Density: g·cm−3 Melting point: °C, Boiling point: °C

There are seven stable isotopes of mercury with Hg-202 being the most abundant. The longest-lived radioisotopes are 194Hg with a half-life of 444 years, and 203Hg with a half-life of days. Most of the remaining radio isotopes have half-lives that are less than a day.

Pure mercury is stable and does not tarnish at ordinary temperatures. It will form alloys with most metals. It is not soluble in water or most other liquids, but will dissolve in lipids (fats and oils). Mercuric chloride and methyl mercury are both soluble in most organic solvents. Mercuric chloride is soluble in water, but methyl mercury is not. It is also a very volatile liquid and extremely so when it reaches 302°C (575K). Mercury is a poor conductor of heat but an alright conductor of electricity.

Mercury readily combines with aluminium to form a mercury- aluminum amalgam when the two pure metals come into contact. However, when the amalgam is exposed to air, the aluminium oxidizes, leaving behind mercury. The oxide flakes away, exposing more mercury amalgam, which repeats the process. This process continues until the supply of amalgam is exhausted, and since it releases mercury, a small amount of mercury can “eat through” a large amount of aluminium over time, by progressively forming amalgam and relinquishing the aluminium as oxide.

The most important salts are: Mercury(I) chloride (AKA calomel) is sometimes still used in medicine and acousto-optical filters; Mercury(II) chloride (which is very corrosive, sublimates and is a violent poison); Mercury fulminate, (a detonator widely used in explosives); Mercury(II) oxide, the main oxide of mercury; Mercury(II) sulfide (AKA cinnabar mercuric ore still used in oriental medicine, or vermilion which is a high-grade paint pigment); Mercury(II) selenide a semiconductor; Mercury(II) telluride a semiconductor; and Mercury cadmium telluride and mercury zinc telluride, infrared detector materials.

Mercury is a very useful element and is used in many different ways. The most common use is in thermometers and barometers. Mercury, depending on temperature and pressure, will rise and fall accordingly. This is how it is used in thermometers and barometers. It is also used in the making of most batteries. In its gaseous form it is used in mercury-vapour lamps and advertising signs. It is used in is the production of caustic soda and chlorine and used in pesticides and antifouling paint. It is also used in dentistry, as the basis for dental amalgams and preparations.

The only way to extract mercury successfully is to heat the compound of cinnabar (HgS or mercury sulfide) in a current of air then condense the vapour.