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Nitrogen is a chemical element; it has symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System.
N 2 fixation has been found in some anoxic systems, generally associated with sulfate reducers or oxidizers. [8] However, heterotrophic denitrification is a more dominant process under anoxic conditions. Denitrification is the reduction of NO 3 − and NO 2 − to the gaseous form of nitrogen (N 2), including the greenhouse gas nitrous oxide (N ...
In general, nitrogen tends to be a limiting ocean nutrient, but in HNLC regions it is never significantly depleted. [1] [2] Instead, these regions tend to be limited by low concentrations of metabolizable iron. [1] Iron is a critical phytoplankton micronutrient necessary for enzyme catalysis and electron transport. [3] [4]
Abundance (atom fraction) of the chemical elements in Earth's upper continental crust as a function of atomic number; [5] siderophiles shown in yellow Graphs of abundance against atomic number can reveal patterns relating abundance to stellar nucleosynthesis and geochemistry.
The nitrogen cycle is an important process in the ocean as well. While the overall cycle is similar, there are different players [40] and modes of transfer for nitrogen in the ocean. Nitrogen enters the water through the precipitation, runoff, or as N 2 from the atmosphere. Nitrogen cannot be utilized by phytoplankton as N
Reactive nitrogen ("Nr"), also known as fixed nitrogen [1], refers to all forms of nitrogen present in the environment except for molecular nitrogen (N 2 ). [ 2 ] While nitrogen is an essential element for life on Earth, molecular nitrogen is comparatively unreactive, and must be converted to other chemical forms via nitrogen fixation before it ...
Solid nitrogen is mainly the subject of academic research, but low-temperature, low-pressure solid nitrogen is a substantial component of bodies in the outer Solar System and high-temperature, high-pressure solid nitrogen is a powerful explosive, with higher energy density than any other non-nuclear material.
Soil gases (soil atmosphere [1]) are the gases found in the air space between soil components. The spaces between the solid soil particles, if they do not contain water, are filled with air. The primary soil gases are nitrogen, carbon dioxide and oxygen. [2] Oxygen is critical because it allows for respiration of both plant roots and soil ...