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Oxygen began building up in the atmosphere at approximately 1.85 Ga. At current rates of primary production, today's concentration of oxygen could be produced by photosynthetic organisms in 2,000 years. [ 4] In the absence of plants, the rate of oxygen production by photosynthesis was slower in the Precambrian, and the concentrations of O 2 ...
The oxygen cycle is the biogeochemical cycle of oxygen atoms between different oxidation states in ions, oxides, and molecules through redox reactions within and between the spheres/reservoirs of the planet Earth. [ 1] The word oxygen in the literature typically refers to the most common oxygen allotrope, elemental/diatomic oxygen (O 2 ), as it ...
It is a good type of flame to use when heating large amounts of material. The flame temperature is high, about 2,000 °C for hydrogen gas in air at atmospheric pressure, [ 11 ] and up to 2800 °C when pre-mixed in a 2:1 ratio with pure oxygen (oxyhydrogen).
Sensor readings seemed to show that oxygen was being made on the seabed 4,000 meters (about 13,100 feet) below the surface, where no light can penetrate. The same thing happened on three ...
Ozone layer. The ozone layer visible from space at Earth's horizon as a blue band of afterglow within the bottom of the large bright blue band that is the stratosphere, with a silhouette of a cumulonimbus in the orange afterglow of the troposphere. The ozone layer or ozone shield is a region of Earth 's stratosphere that absorbs most of the Sun ...
The atmosphere of Earth is composed of a layer of gas mixture that surrounds the Earth's planetary surface (both lands and oceans ), known collectively as air, with variable quantities of suspended aerosols and particulates (which create weather features such as clouds and hazes ), all retained by Earth's gravity.
Oxygen is a chemical element; it has symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is the most abundant element in Earth's crust, and after hydrogen and helium, it ...
Ionizing radiation. Ionizing radiation (US, ionising radiation in the UK), including nuclear radiation, consists of subatomic particles or electromagnetic waves that have sufficient energy to ionize atoms or molecules by detaching electrons from them. [1] Some particles can travel up to 99% of the speed of light, and the electromagnetic waves ...