What is Oxygen? | Types, Definition, Structure, Function & Facts
What is Oxygen?
Oxygen is an important element that is needed by most life forms on Earth to survive. It is the third most abundant element in the universe and the most abundant element in the human body. Oxygen has 8 electrons, and 8 protons. It is located at the top of column 16 in the periodic table.
The oxygen cycle plays an important role in life on Earth. Click here to read more about the oxygen cycle.
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Characteristics and Properties
At standard conditions, oxygen forms a gas consisting of molecules made up of two oxygen atoms (O2). This is called a diatomic gas. In this form, oxygen is a colorless, odorless and tasteless gas.
Oxygen also exists as isotropic ozone (O3). Ozone exists in the upper region of the earth’s atmosphere forming the ozone layer that helps protect us from the harmful rays of the sun.
Oxygen is a very reactive element in its pure state and can form compounds from many other elements. Oxygen readily dissolves in water.
Highlights of Oxygen:
| Symbol | O |
| Atomic Number | 8 |
| Atomic Weight | 15.999 |
| Classification | Gas and nonmetal |
| Phase at Room Temperature | Gas |
| Density | 1.429 g/L |
| Melting Point | 218.79°C, -361.82°F |
| Boiling Point | 182.95°C, -297.31°F |
| Discovered by | Joseph Priestley in 1774 and C. W. Scheele independently in 1772 |
Where is Oxygen found on Earth?
Oxygen is all around us. It is one of the most important elements of planet Earth. Oxygen makes up about 21% of the Earth’s atmosphere and 50% of the mass of the Earth’s crust. Oxygen is one of the atoms that make up water (H2O).
Oxygen is an essential element for life on Earth. It is the most abundant element in the human body, accounting for about 65% of body mass.
How is Oxygen used today?
Oxygen is used by animals and plants during respiration (respiration). Oxygen cylinders are used medically to treat people with breathing problems. They are also used to provide life support to astronauts and divers.
Much of the oxygen used in industry is used in steelmaking. Other uses include creating new compounds such as plastics and generating very hot flames for welding. Liquid oxygen is combined with liquid hydrogen to create rocket fuel.
How was Oxygen discovered?
Swedish chemist C.W. Scheele first discovered oxygen in 1772. He called this gas “fire air” because it was needed for fire to burn. Scheele did not publish his results immediately, and the element was independently discovered by British scientist Joseph Priestley in 1774.
Where did Oxygen get its name?
The name oxygen comes from the Greek word “oxygens” which means “acid maker”. It is so called because early chemists believed that oxygen was necessary for all acids.
Isotopes
There are three stable isotopes of oxygen. More than 99% of stable oxygen consists of the isotope oxygen-16.
Interesting Facts about Oxygen
Oxygen dissolves more readily in cold water than in hot water.
Water can be converted to hydrogen and oxygen by electrolysis.
Oxygen present in the air is produced by photosynthesis. Without plants, there would be very little oxygen in the air.
In the solar system, only Earth has a high percentage of oxygen.
Oxygen atoms are an essential part of proteins and DNA in our bodies.
The process of combining oxygen with other atoms to form compounds is called oxidation.