Search results
Results from the WOW.Com Content Network
Reactive oxygen species, such as superoxide ion (O − 2) and hydrogen peroxide (H 2 O 2), are reactive by-products of oxygen use in organisms. [70] Parts of the immune system of higher organisms create peroxide, superoxide, and singlet oxygen to destroy invading microbes.
In aerobic organisms the energy needed to fuel biological functions is produced in the mitochondria via the electron transport chain. Reactive oxygen species (ROS) with the potential to cause cellular damage are produced along with the release of energy.
This is the energy per mole necessary to remove electrons from gaseous atoms or atomic ions. The first molar ionization energy applies to the neutral atoms. The second, third, etc., molar ionization energy applies to the further removal of an electron from a singly, doubly, etc., charged ion.
However, this ion is unstable, because it has an incomplete valence shell around the nitrogen atom, making it a very reactive radical ion. Due to the instability of radical ions, polyatomic and molecular ions are usually formed by gaining or losing elemental ions such as H + , rather than gaining or losing electrons.
In carbon monoxide (CO, isoelectronic with dinitrogen) the oxygen 2s orbital is much lower in energy than the carbon 2s orbital and therefore the degree of mixing is low. The electron configuration 1σ 2 1σ* 2 2σ 2 2σ* 2 1π 4 3σ 2 is identical to that of nitrogen. The g and u subscripts no longer apply because the molecule lacks a center ...
Free nitrogen atoms easily react with most elements to form nitrides, and even when two free nitrogen atoms collide to produce an excited N 2 molecule, they may release so much energy on collision with even such stable molecules as carbon dioxide and water to cause homolytic fission into radicals such as CO and O or OH and H. Atomic nitrogen is ...
The latter property manifests in the capacity of nitrogen to form usually strong hydrogen bonds, and its preference for forming complexes with metals having low electronegativities, small cationic radii, and often high charges (+3 or more). Nitrogen is a poor oxidising agent (N 2 + 6e − → 2NH 3 = −0.057 V at pH 0).
g singlet oxygen (second excited state), and 3 Σ − g triplet oxygen (ground state). The lowest energy 1s molecular orbitals are uniformly filled in all three and are omitted for simplicity. The broad horizontal lines labelled π and π* each represent two molecular orbitals (for filling by up to 4 electrons in total).