A colorless, odorless reactive gas, the chemical element of atomic number 8 and the life-supporting component of the air. Oxygen forms about 20 percent of the earth's atmosphere, and is the most abundant element in the earth's crust, mainly in the form of oxides, silicates, and carbonates.
- ‘There may also be a greatly reduced oxygen content in the air at the bottom of deep wells.’
- ‘Solar panels power an electrolyser that separates water into hydrogen and oxygen.’
- ‘On the one hand, there is the body's need for oxygen and its supply from the lungs.’
- ‘The heart muscle is supplied with oxygen by blood arriving in the coronary arteries.’
- ‘The chemicals in tobacco reduce the flow of oxygen around the mother's blood stream.’
- ‘Copper reacts with oxygen and carbon dioxide to form a greenish patina of copper carbonate.’
- ‘Energy is generated by the reaction of hydrogen and oxygen across a catalytic membrane.’
- ‘It is important to minimize the new wine's exposure to oxygen, whatever its colour.’
- ‘Therefore in light plants gave out oxygen, but in the dark they emitted carbon dioxide.’
- ‘In other words, it is possible to die from a lack of oxygen, because of ozone poisoning.’
- ‘In addition, the very reactive singlet oxygen can be generated by an input of energy.’
- ‘To avoid the production of oxygen via photosynthesis, plants were kept in the dark.’
- ‘There seems to be less oxygen in town air on a very hot day, even in a quiet corner like Bath Place.’
- ‘Despite the addition of oxygen and the issue of potash cartridges, the air is foul.’
- ‘Iron is needed to produce more blood to supply the baby with the necessary nutrients and oxygen.’
- ‘This oxygen may also support nitrifying bacteria that convert ammonia to nitrate.’
- ‘The air in this chamber is very low in oxygen, so divers are advised not to remove their regulators.’
- ‘This maintained the same concentration of oxygen in the gas flow at the point of analysis.’
- ‘He also had difficulty breathing and had to be given oxygen on arrival at hospital.’
- ‘It results from a temporary reduction in blood and oxygen supply to part of the brain.’
Late 18th century: from French ( principe) oxygène ‘acidifying constituent’ (because at first it was held to be the essential component in the formation of acids).
We take a look at several popular, though confusing, punctuation marks.