The Element Discoveries (1 A.D. to 1775)

Copper

9000 BCE

Copper has been known since prehistoric time. It has been mined for more than 5000 years. Mankind has used the metal since at least 9000 BC in the Middle East. A copper pendant dated to 8700 BC was found in Iraq. Scientists believe only iron from meteorites and gold were used by people earlier than copper.

Tin

3500 BCE

Tin has been known since ancient times. The first tin alloy to gain widespread use was bronze, an alloy of tin and copper. Humans knew how to make bronze as early as 3000 BCE.

Gold

3000 BCE

Gold has been known since prehistoric times and was one of the first metals to be worked, mainly because it was to be found as nuggets or as particles in the beds of streams.

Silver

3000 BCE

Silver is a transition metal with element symbol Ag and atomic number 47. The element is found in jewelry and currency for its beauty and value and in electronics for its high conductivity and malleability. Known since prehistoric time. Man learned to separate silver from lead as early as 3000 B.C.

Iron

1500 BCE

Ancient Egyptian iron objects have been dated to around 3500 B.C. These objects also contain approximately 8% nickel showing the iron may have originally been part of a meteorite. The "Iron Age" began around 1500 B.C. when the Hittites of Asia Minor began to smelt iron ore and make iron tools.

Mercury

1500 BCE

Mercury was known to the ancient Chinese, Egyptians and Hindus and has been found in Egyptian tombs dating back to about 1500 B.C. In the fourth century B.C. we find Aristotle refers to mercury in writing as 'hydro-argyros' – which translates as liquid-silver or water-silver.

Phosphorus

1669

Phosphorus was first made by Hennig Brandt in Hamburg in Germany in 1669. When he evaporated urine and heated the residue until it was red hot.

Carbon

1754

In 1754, Joseph identified what he called "fixed air" (now known to be carbon dioxide) because it could be returned, or fixed, into the sort of solids from which it was produced.

Hydrogen

1766

Hydrogen was discovered by the English physicist Henry Cavendish in 1766. Scientists had been producing hydrogen for years before it was recognized as an element.

Oxygen

1774

British Minister Joseph Priestley and French Tax Administrator Antoine Lavoisier, together discover a fantastic new gas called oxygen.

Chlorine

1774

Discovered in 1774 by Carl Wilhelm Scheele, who mistakenly thought it contained oxygen. Chlorine was given its name in 1810 by Humphry Davy, who insisted that it was in fact an element. The pure chemical element has the physical form of a diatomic green gas.

Magnesium

1775

Recognized as an element by Black 1775; Isolated by Sir Humphrey Davy 1808 (England). Magnesium first came into use as magnesium sulfate or Epsom salt. The story goes that in 1618 a farmer in Epsom, England could not get his cattle to drink from a well with bitter-tasting water, yet the water seemed to heal skin conditions. The substance in the water (magnesium sulfate) came to be known as Epsom salts.

Potassium

1807

The potassium name with which Humphry Davy baptized it when he discovered it in 1807, was the first metallic element isolated by electrolysis.

Sodium

1807

Sodium was first isolated in 1807 by Sir Humphry Davy, who made it by the electrolysis of very dry molten sodium hydroxide, NaOH.

Invention of the periodic table

1869

Dmitri Mendeleev (1834-1907) is the inventor of the periodic table from which the current one starts.