oxygen

[ ok-si-juh n ]
/ ˈɒk sɪ dʒən /

noun Chemistry.

a colorless, odorless, gaseous element constituting about one-fifth of the volume of the atmosphere and present in a combined state in nature. It is the supporter of combustion in air and was the standard of atomic, combining, and molecular weights until 1961, when carbon 12 became the new standard. Symbol: O; atomic weight: 15.9994; atomic number: 8; density: 1.4290 g/l at 0°C and 760 mm pressure.

Origin of oxygen

1780–90; < French oxygène, equivalent to oxy- oxy-1 + -gène -gen

OTHER WORDS FROM oxygen

ox·y·gen·ic [ok-si-jen-ik] /ˌɒk sɪˈdʒɛn ɪk/, ox·yg·e·nous [ok-sij-uh-nuh s] /ɒkˈsɪdʒ ə nəs/, adjective ox·y·gen·ic·i·ty [ok-si-juh-nis-i-tee] /ˌɒk sɪ dʒəˈnɪs ɪ ti/, noun

Words nearby oxygen

oxychromatic, oxycodone, oxycodone hydrochloride, oxycontin, oxyesthesia, oxygen, oxygen acid, oxygen affinity hypoxia, oxygen bar, oxygen capacity, oxygen consumption

Example sentences from the Web for oxygen

British Dictionary definitions for oxygen

oxygen
/ (ˈɒksɪdʒən) /

noun

  1. a colourless odourless highly reactive gaseous element: the most abundant element in the earth's crust (49.2 per cent). It is essential for aerobic respiration and almost all combustion and is widely used in industry. Symbol: O; atomic no: 8; atomic wt: 15.9994; valency: 2; density: 1.429 kg/m³; melting pt: –218.79°C; boiling pt: –182.97°C
  2. (as modifier)an oxygen mask

Derived forms of oxygen

oxygenic (ˌɒksɪˈdʒɛnɪk) or oxygenous (ɒkˈsɪdʒɪnəs), adjective

Medical definitions for oxygen

oxygen
[ ŏk′sĭ-jən ]

n. Symbol O

An element constituting 21 percent of the atmosphere by volume that occurs as a diatomic gas, O2, combines with most elements, is essential for plant and animal respiration, and is required for nearly all combustion. Atomic number 8.
A medicinal gas used therapeutically for oxygen supplementation, containing not less than 99.0 percent, by volume, of O2.

Scientific definitions for oxygen

oxygen
[ ŏk′sĭ-jən ]

O

A nonmetallic element that exists in its free form as a colorless, odorless gas and makes up about 21 percent of the Earth's atmosphere. It is the most abundant element in the Earth's crust and occurs in many compounds, including water, carbon dioxide, and iron ore. Oxygen combines with most elements, is required for combustion, and is essential for life in most organisms. Atomic number 8; atomic weight 15.9994; melting point -218.8°C; boiling point -182.9°C; gas density at 0°C 1.429 grams per liter; valence 2. See Periodic Table.

Word History

In 1786, the French chemist Antoine Lavoisier coined a term for the element oxygen (oxygène in French). He used Greek words for the coinage: oxy- means “sharp,” and -gen means “producing.” Oxygen was called the “sharp-producing” element because it was thought to be essential for making acids. Lavoisier also coined the name of the element hydrogen, the “water-producing” element, in 1788. Soon after, in 1791, another French chemist, J. A. Chaptal, introduced the word nitrogen, the “niter-producing” element, referring to its discovery from an analysis of nitric acid.

Cultural definitions for oxygen

oxygen

An element, normally a gas, that makes up about one-fifth of the atmosphere of the Earth. Oxygen is usually found as a molecule made up of two atoms. Its symbol is O.

notes for oxygen

When we breathe in oxygen, it is carried by the hemoglobin in our blood throughout the body, where it is used to generate energy by oxidation. ( See respiration.)

notes for oxygen

Oxygen is a waste product of green plants and photosynthesis.