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Oxygen is a chemical element whose most common form is in the gaseous state. As a gas, oxygen has no odor, color, or taste. In the liquid state, oxygen is light blue in color. It consists of molecules in which there are two oxygen atoms bonded together and which are represented as O–O or O 2 . Therefore, when mentioning this element, reference can be made to a single oxygen atom, to a single O 2 molecule , or to a sample containing O 2 molecules .
Some interesting facts about oxygen are mentioned below.
Oxygen is the most abundant element on Earth
The air that many living things breathe contains 78% nitrogen, 21% oxygen and 1% other elements. Each water molecule on the planet present in rivers, seas, lakes, lagoons, among others, contains an oxygen atom that is captured by various aquatic organisms to breathe. Part of the rocks that make up the earth’s surface are made up of minerals composed of oxides of different elements. In short: oxygen is found in many parts of the Earth.
Oxygen is of extraterrestrial origin
Oxygen is formed inside stars larger than the Sun, through a cycle called CNO that produces carbon, nitrogen and oxygen. When these stars reach the end of their life cycle, they explode and release such elements into outer space. For this reason, oxygen is the third most abundant element in the universe, after hydrogen and helium.
Oxygen did not originate at the same time as the formation of the Earth
Earth’s atmosphere originated when gases from volcanic eruptions and colliding bodies from space were trapped by the force of gravity from the planet that had already formed. These gases formed a primitive atmosphere that lacked oxygen and contained carbon dioxide and monoxide, methane, ammonia, and water vapor. Over time, organisms that perform photosynthesis released oxygen into the environment, which accumulated and allowed the formation of the ozone layer and the current atmosphere.
Oxygen is very reactive
Oxygen is the second most electronegative element. Electronegativity refers to the ability of an atom to attract electrons from other atoms to bond and form compounds. Due to this characteristic, oxygen reacts with most of the known elements.
Oxygen is essential for aerobic organisms, that is, those that depend on this gas to breathe.
When oxygen enters cells, it is conducted to organelles called mitochondria. There, it reacts with glucose from photosynthesis (in autotrophic organisms such as plants, algae, and some bacteria) or from food (in heterotrophic organisms such as humans). This reaction releases molecules of adenosine triphosphate or ATP, which is the molecule that provides energy to the body, essential to carry out vital functions.
Oxygen protects living beings from the most harmful solar radiation
Radiation is a form of energy emitted as waves or particles. In the stratosphere, a type of radiation called ultraviolet ( UV ) splits molecular oxygen (O 2 ). The resulting atoms are very reactive, and can join O 2 molecules that have not yet been split, forming ozone ( O 3 ). UV rays can also split O 3 molecules apart, leaving O 2 and O as a result. This destruction and constant creation of ozone protects organisms from ultraviolet radiation, since all of this is absorbed by oxygen atoms and therefore It does not reach the earth’s surface.
Sources
Biggs, A., Hagins, W.C., Holliday, W.G., Kapicka, C.L., Lundgren, L., Haley, A., Rogers, W.D., Sewer, M.B., Zike, D. Biology . Glencoe/McGraw-Hill., Mexico, 2011.
Zumdahl, S. Fundamentals of Chemistry. 2nd edition. McGraw Hill Inter-American., Mexico, 2007.
