# oxygen

Pronunciation: say "OK-si-juhn" US /ˈɑksɪd͡ʒən/, UK /ˈɒksɪd͡ʒən/

## Noun

1. Molecular oxygen (O₂), a colorless, odorless gas at room temperature made of two bonded oxygen atoms; also called dioxygen.
   - Simple: A clear gas with no color or smell that animals breathe to live, made of two atoms joined together.
   - _At room temperature, oxygen exists as a stable two-atom molecule that fuels combustion and respiration._
   - _Plants release oxygen into the atmosphere as a byproduct of photosynthesis._
2. A chemical element (symbol O) with atomic number 8 and relative atomic mass 15.9994, occurring as a colorless, odorless gas.
   - Simple: A basic chemical element that living things need, found as a clear gas with no color or smell.
   - _Oxygen ranks as the third most abundant element in the universe by mass._
   - _Nearly half of Earth's crust by weight consists of oxygen bound into minerals._
3. A mixture of oxygen and other gases administered to a patient to ease or support breathing.
   - Simple: A breathing gas with extra oxygen, given to a sick or injured person to help them breathe.
   - _Paramedics administered oxygen at the scene before moving the accident victim._
   - _After surgery, she was kept on oxygen until her breathing stabilized._
4. A supportive condition or environment that allows something (a movement, an idea, a business) to survive and flourish.
   - Simple: Whatever something needs to grow and stay alive, such as money, support, or attention.
   - _Media coverage provided the oxygen that kept the protest movement alive for months._
   - _Starved of investment, the startup gasped for the oxygen of fresh capital._
5. A single atom of oxygen, the unit that combines with other atoms to form molecules.
   - Simple: A single one of the tiny particles that make up the element oxygen.
   - _Each molecule of water links two hydrogen atoms to a single oxygen._
   - _Carbon dioxide pairs two oxygens with one central carbon atom._

## Origin

Borrowed from French oxygène, a term suggested by Lavoisier for the "acidifying principle," from Ancient Greek ὀξύς (oxús, "sharp") plus γένος (génos, "birth"), reflecting the belief that oxygen played a role in forming acids.

Source: DictionaryAI, https://dictionaryai.com/define/oxygen (written from Wiktionary data, CC BY-SA 4.0: https://creativecommons.org/licenses/by-sa/4.0/).