Comet 2022 E3 (ZTF) Sissi, the Empress The best astronomical photos of 2022 Childhood in the Middle Ages The best aurora photos of the year The best destinations to travel to in 2023
YOU MAY BE INTERESTED IN:
Tests Videos Dinosaurs Climate change Animals Agenda 2023 DNA
Science Chemistry
Updated December 15, 2022, 12:35 PM
Share
Editor and journalist specializing in science and nature
Oxygen is a chemical element with atomic number 8, which means that each oxygen atom has 8 protons in its atomic nucleus. It is represented by the symbol O and is found in group 16 and period 2 of the periodic table, Therefore, it belongs to the group of non-metals. On Earth, at standard temperature and pressure, two atoms of the element combine to form dioxygen, a colorless, odorless, and tasteless gas with formula O2.
Only behind hydrogen and helium, oxygen is the third most abundant element in the universe, as well as the most abundant element in the Earth's crust. It is also More than one-fifth of the air in Earth's atmosphere, 21%, is oxygen. However, this has not always been the case in the history of the Earth, since today we know almost with certainty that most of the oxygen in the Earth's atmosphere It comes from an event that took place about 2.8 billion years ago, when the first oxygen-producing microorganisms, the so-called cyanobacteria, emerged.
The authorship of the discovery of oxygen is a disputed fact. In 1772, the chemist Carl Wilhelm Scheele had already independently discovered oxygen, which he referred to as air of fireHowever, chemist Joseph Priestly published his work describing the element earlier, so he is the one who is credited with its discovery. The name oxygen comes from the Greek roots “oxys” which means “acid” and “genes“, “generator”It is attributed to the chemist Antoine Lavoisier, who believed that it was an essential element for the generation of acids.
Although oxygen is essential for life, at high concentrations it can be toxic to living beings due to its high oxidizing capacity. For example, prolonged exposure to high levels of oxygen can cause nausea, dizziness, muscle spasms, convulsions, and loss of vision and consciousness. It can also irritate the lungs, causing coughing or respiratory failure. Some substances, such as peroxides and certain hydroxyl radicals, can also be highly toxic.
Oxygen in its form of ozone (O3) can also be highly harmful when it's present in the atmosphere at ground level, as breathing ozone can cause coughing, throat irritation, and worsening of conditions such as asthma and bronchitis. Prolonged and regular exposure to ozone can even lead to permanent lung damage or the development of emphysema.
Despite its few harmful effects, oxygen is the most important gas for humans and can also be used to treat certain conditions through what is known as oxygen therapy. This involves providing additional oxygen through a device to treat everything from burns, serious wounds, injuries, and infections to embolisms, carbon monoxide poisoning, and decompression sickness, which is suffered by divers.
Oxygen accounts for approximately 21% by volume of the Earth's atmosphere and is an essential element for life on Earth. In fact, all aerobic organisms on our planet, including animals and some bacteria, They take oxygen from the atmosphere to breathe and return it in the form of carbon dioxide. Green plants, which form the basis of food chains on Earth, assimilate this carbon dioxide and, through photosynthesis, release free oxygen in the presence of sunlight. In fact, most of the free oxygen in the atmosphere comes from photosynthetic activity. In water, dissolved oxygen is found at a rate ranging from 7.5 to 14.5 milligrams per liter, allowing aquatic organisms to respire underwater.
Oxygen is also essential in the form of ozone, (O3),which forms the protective layer that surrounds the Earth in the stratosphere, filtering ultraviolet radiation and preventing it from reaching living beings. However, when ozone settles in the lower layers of the atmosphere at high concentrations, it can have very harmful effects—especially respiratory—on the health of people and plants.
Subscribe to National Geographic at -33% and receive a FREE LEFRIK backpack. Cancel anytime.
Share your National Geographic experience. Give the gift of a subscription at the best price today.
Related
Hector Rodriguez
Hector Rodriguez
Javier Flores
Javier Flores
Gabriel Pinto, scientific advisor
Hector Rodriguez
Hector Rodriguez
Hector Rodriguez
Hector Rodriguez
MOST VIEWED
Sign up for the newsletters you're most interested in and receive the best stories, photos, and news delivered to your email every week for free.
Subscribe
Feed your curiosity for only €59.95 per year
Explore new destinations for only €59.95 per year
Take another step in history for only €59.95 per year
CHEMICAL ELEMENTS
PLANETS
ANIMALS
PROPER NAMES
Follow us
Facebook
Twitter
Instagram
Pinterest
SUBSCRIBE AND BE PART OF THE CHANGE
National Geographic
National Geographic Travel
National Geographic History
Feed your curiosity
for only €59.95 per year
SUBSCRIBE
Explore new destinations
for only €59.95 per year
SUBSCRIBE
Take another step in history
for only €59.95 per year
SUBSCRIBE
SUBSCRIBE NOW AND GET A GIFT
English 
Spanish