substance

oxygen

Oxygen is a chemical element essential for respiration and a key component in water and various chemical processes.
11 related articles · 1 formulas · 3 who worked here

Description

Oxygen is an invisible gas that fills our lungs with every breath. It is like a magical elixir of life: without it, fire goes out and fish in water stop breathing. Oxygen is born in the green leaves of plants under the sun, as a gift to us from generous nature.

History

Oxygen was first isolated by Scheele (1771) and Priestley (1774), but the decisive role was played by Lavoisier (1777), who refuted the phlogiston theory and showed that air consists of two gases: 'vital' (oxygen) and 'asphyxiating' (nitrogen). In 1781, Cavendish synthesized water from hydrogen and oxygen. In the 20th century, the Nobel Prize was awarded to Otto Warburg (1931) for his work on the respiratory enzyme using oxygen.

How it works

In mitochondria, oxygen serves as the final electron acceptor in the electron transport chain, being reduced to water. This process, coupled with ATP synthesis, obeys the second law of thermodynamics: the energy of chemical bonds in food is converted into the energy of high-energy phosphate bonds in ATP with heat dissipation. Without oxygen, the cell switches to anaerobic glycolysis, which is 18 times less efficient.

Fun fact

Oxygen is the most abundant element on Earth: it makes up almost half the mass of the Earth's crust and two-thirds of your body's mass. And it is oxygen that colors blood red by combining with iron.

Concept graph →

Formulas

$$\mathrm{C}/\mathrm{O} \approx 1$$
Carbon to oxygen abundance ratio is approximately unity.
What is in the formula
CvariableCarbon abundance — abundance
OvariableOxygen abundance — abundance
c/o\approx1 · 2510.04863

Related articles · 21

Materials2026-09-022 minarXiv:2609.02629
Vacancies line up and open the way for current
A transparent film of bismuth tungstate sits on a substrate and does not conduct electricity. Three minutes in a cloud of nitrogen plasma, and it turns black, with resistance dropping by a factor of a billion.
Materials2026-08-201 minarXiv:2608.20199express
Oxygen Impurities in Superconductors: Seeing the Unseen
A superconductor is a material that conducts electricity without loss, like water flowing through a perfectly smooth pipe. In copper-based superconductors, tiny oxygen additions act like a volume knob: a bit more and the material starts superconducting; a bit less and it stops. But the oxygen atoms themselves are so small that seeing them directly was impossible.
Materials2026-08-201 minarXiv:2608.20199express
Oxygen Impurities in Superconductors: Seeing the Unseen
A superconductor is a material that conducts electricity without loss, like water flowing through a perfectly smooth pipe. In copper-based superconductors, tiny oxygen additions act like a volume knob: a bit more and the material starts superconducting; a bit less and it stops. But the oxygen atoms themselves are so small that seeing them directly was impossible.
Chemical Physics2026-08-081 minarXiv:2608.08050express
A Lingering Aftertaste on Platinum Nanoparticles
Turn off the stove, and water stops boiling almost instantly. In the world of catalysis, researchers expected a similar picture: stop the reaction, and all intermediate particles vanish right away. But fresh observations of platinum nanoparticles tell a different story.
Medical Physics2026-07-202 minarXiv:2607.17974express
Oxygen Decides Whether Ultrafast Radiation Saves Tissues
A camera flash that fires in a thousandth of a second doesn't heat the subject — unlike a regular flash that lasts a full second. A similar trick has been found in radiotherapy: when a radiation dose is delivered in milliseconds instead of minutes, healthy tissues suffer less. This is called the FLASH effect.
Chemical Physics2026-06-112 minarXiv:2606.13660express
Light Twists Current to Extract Oxygen
Water in a glass seems simple, but to split it into oxygen and hydrogen with sunlight, it's not enough to just transfer electrons: they also need to 'agree' on the direction of their spin. An oxygen molecule is born with two unpaired electrons spinning in the same direction.
Strongly Correlated2026-05-041 minarXiv:2605.02891express
The Oxygen Key to Superconductivity
A layered cake of atomic planes of nickel and oxygen: that's how bilayer nickelates are built. Two such planes are separated by a spacer layer. If an oxygen atom sits in that spacer, it acts as a bridge: it links the layers and triggers a state in which electrons move without resistance.
Materials2026-05-011 minarXiv:2605.01045express
How Water Turns into Alkali and Back
In a crystal of water and caustic cesium, oxygen and cesium atoms sit in place like beads in a rigid lattice. Hydrogen atoms behave differently: they are like passengers constantly changing seats. In this layered material, each oxygen is linked to three neighbors via hydrogen bridges, forming a honeycomb-like pattern.
Exoplanets2026-04-282 minarXiv:2604.25263express
Oxygen Memory of Chondrules
Chondrules look like frozen raindrops made of stone. They're about the size of a grain of sand, but they record the history of the first few million years of the Solar System. Once, these droplets floated in the scorching gas around the young Sun, then clumped into asteroids and fell to Earth as meteorites.
Chemical Physics2026-04-031 minarXiv:2604.03464express
How Water Dances with Carbon Rings
A water molecule, finding itself near a carbon ring, starts to vibrate, and immediately falls under the sway of an invisible conductor. The ring's electron cloud, like a maestro, dampens some vibrations while amplifying others.
Chemical Physics2026-03-262 minarXiv:2603.24924express
Hydrogen from Algae: A Green Light for Clean Energy
Conventional solar panels convert light into electricity, but here light splits water into hydrogen and oxygen. Hydrogen is a clean fuel, but the process is slow. To speed it up, helper substances that donate electrons are added. Often this is alcohol, but it's a shame to waste it.
Exoplanets2026-03-191 minarXiv:2603.18769express
Acid for Life: Why Cyanide Is No Obstacle
At the dawn of Earth, about four billion years ago, the planet was a harsh place: a dim sun, frequent asteroid impacts, and air without oxygen. Under such conditions, the first steps of life seem almost impossible.
Materials2026-02-261 minarXiv:2602.22869express
Gray film, green hydrogen
Hydrogen is a clean fuel: when it burns, it produces only water. But to extract it from water, you need to break the strong bond between hydrogen and oxygen. This is usually done with platinum, an expensive metal.
Stellar2026-02-181 minarXiv:2602.16394express
Stellar Ashes and Oxygen-18
Two burned-out stellar cores collide and merge into one. That's how R Coronae Borealis stars are born — rare luminaries where oxygen-18 is hundreds of times more abundant than in the Sun. But exactly how this happens has remained a puzzle.
Space Physics2026-01-211 minarXiv:2601.14719express
Lunar Oxygen: Breathing Without Earth
Lunar dust looks like gray sand, but there's not a breath of air in it. Oxygen is there — tightly bound in the rocks, like sugar in caramel. To get it out, you need to break chemical bonds, and scientists are looking for the simplest way. In the lab, they took artificial lunar soil made from samples from the Apollo missions and China's Chang'e.
Chemical Physics2026-01-172 minarXiv:2601.11936express
How the Tiniest 'Invisible Molecule' Shatters Apart
In the air we breathe, invisible chemical events are constantly unfolding. One of them is the birth and instant death of a particle with the formula H₂COO. Known as an 'intermediate,' it appears for a split second when ozone molecules collide with organic compounds, then immediately shatters into simpler fragments.
Exoplanets2026-01-131 minarXiv:2601.08390express
q-bio.BM2026-01-092 minarXiv:2601.14273express
Oxygen from Water: How Plants Build It Brick by Brick
In every leaf, in the light, a factory works that splits water into oxygen and hydrogen. The oxygen goes into the air we breathe, and the plant uses the hydrogen for food. The heart of this factory is a protein complex with four manganese atoms and one calcium atom.
Exoplanets2026-01-052 minarXiv:2601.02548express
Oxygen Dead End in a Red Dwarf System
On the exoplanet TRAPPIST-1, oxygenic photosynthesis, the process by which light energy is converted into chemical energy with oxygen as a byproduct, is losing the race for survival. This M-dwarf star emits mostly in the infrared, not in the visible range like the Sun.
Stellar2025-10-041 minarXiv:2510.03916express
Record CO₂: When the Planet's Lungs Held Their Breath
The carbon cycle is like the planet's breathing. Forests and oceans inhale carbon dioxide, while industry and wildfires exhale it back. In 2023, that inhale became gasping and shallow. At the Mauna Loa station, instruments recorded that CO₂ concentrations rose by 3.37 parts per million over the year, 86% faster than the year before.