Oxygen

Oxygen

There are 117 known elements in the periodic table. Out of all of these, the single most important (in my opinion), is oxygen. Why? The answer is simple. Without oxygen, human beings would not be able to live. Oxygen is the main component in the air we breathe, making it essential to the respiration of all animals. It is also found in the compound, H2O (water), which is essential to the life of most all organisms.

Oxygen, chemical symbol “O”, is a colorless, odorless, tasteless element. It is a gas at room temperature, making it classified as a non-metal. It is located in group 6A, second period, and is atomic number 8. It has eight protons, electrons, and neutrons. Its atomic weight is 15.994, and its atomic volume is 14.0 cm3/mol. The boiling point of oxygen is -297.31 degrees Fahrenheit, and the melting point is -361.82 degrees Fahrenheit.

The discovery of oxygen has been credited to two different scientists. The scientist who discovered it first was Carl William Scheele, a Swedish pharmacist and chemist, in 1772. He conducted an experiment, heating mercuric oxide and various nitrates to isolate the element. However, his discoveries were not published until 1777, I the book, Treatise on Air and Fire. Joseph Priestly, a British clergymen, discovered the element on August 1, 1774. He conducted an experiment in which a focused sunlight on a glass tube filled with mercuric nitrate. This produced a gas which he named, 'dephlogisticated air'. He acknowledged that candles burned brighter in presence of the gas, and that a mouse which breathed lived longer and was more active. He published his discoveries in a paper, “An Account of Further Discoveries in Air", in 1775. He also later included his findings in the book, Experiments and Observations on Different Kinds of Air. Because he published his discoveries first, he is usually acknowledged for oxygen’s discovery.

Antoine Lavoisier also contributed to society’s knowledge of oxygen. He conducted the first legitimate experiments on oxidation, and was also the first to correctly explain combustion. He also used experiments similar to those of Priestly and Scheele, in order to prove that the gas the two scientists discovered was indeed a chemical element. In one of his experiments, he proved that air is made up of two chemical elements, which we now know to be oxygen and nitrogen. Lavoisier later named the gas, oxygen, after the Greek words “oxys”, and “genes”.

As previously stated, oxygen is a very important element. It is the most abundant element at the earth’s surface, found in various ores, gems, and also in living organisms. Oxygen makes up 21% of the earth’s atmosphere, and also makes up 46% of the earth’s mass. Approximately two-thirds of the human body and nine-tenths of water is made of the element.