Discovery date : 1774
Discovered by: Joseph Priestley in Wiltshire, England
and independently by Carl Wilhelm Scheele in Uppsala, Sweden.
Origin of the name: The name comes from the Greek 'oxy genes', meaning acid forming.
Allotropes : O2, O3
~>OXYGEN is a chemical element with symbol O and atomic number 8. It is a member of the chalcogen group on the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds.
| FACT BOX | |||
| Group | 16 | Melting point | −218.79°C, −361.82°F, 54.36 K |
| Period | 2 | Boiling point | −182.962°C, −297.332°F, 90.188 K |
| Block | p | Density (g cm−3) | 0.001308 |
| Atomic number | 8 | Relative atomic mass | 15.999 |
| State at 20°C | Gas | Key isotopes | 16O |
| Electron configuration | [He] 2s22p4 | CAS number | 7782-44-7 |
| ChemSpider ID | 140526 | ChemSpider is a free chemical structure database | |
In 1608, Cornelius Drebbel had shown that heating saltpetre (potassium nitrate, KNO3) released a gas. This was oxygen although it was not identified as such.
The credit for discovering oxygen is now shared by three chemists: an Englishman, a Swede, and a Frenchman. Joseph Priestley was the first to publish an account of oxygen, having made it in 1774 by focussing sunlight on to mercuric oxide (HgO), and collecting the gas which came off. He noted that a candle burned more brightly in it and that it made breathing easier. Unknown to Priestly, Carl Wilhelm Scheele had produced oxygen in June 1771. He had written an account of his discovery but it was not published until 1777. Antoine Lavoisier also claimed to have discovered oxygen, and he proposed that the new gas be called oxy-gène, meaning acid-forming, because he thought it was the basis of all acids.