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Hydrogen-alpha, typically shortened to H-alpha or Hα, is a deep-red visible spectral line of the hydrogen atom with a wavelength of 656.28 nm in air and 656.46 nm in vacuum. It is the first spectral line in the Balmer series and is emitted when an electron falls from a hydrogen atom's third- to second-lowest energy level.
Each hydrogen added to a molecule can be considered as a proton plus a one-electron reduction of the redox state, while each oxygen counts as a two-electron oxidation. Thus a net addition of H 2 O is a simple hydration with no net change in redox state and frequently occurs reversibly in aqueous solution.
The α-carbon (alpha-carbon) refers to the first carbon atom that attaches to a functional group, such as a carbonyl. The second carbon atom is called the β-carbon ( beta -carbon), the third is the γ-carbon ( gamma -carbon), and the naming system continues in alphabetical order.
By some definitions, "organic" compounds are only required to contain carbon. However, most of them also contain hydrogen, and because it is the carbon-hydrogen bond that gives this class of compounds most of its particular chemical characteristics, carbon-hydrogen bonds are required in some definitions of the word "organic" in chemistry. [92]
The nucleus of the helium-4 atom is identical with an alpha particle. High-energy electron ... air and around 65% that of hydrogen. ... air or nitrogen. [28] A number ...
Molecular ion peaks are also often preceded by an M-1 or M-2 peak resulting from loss of a hydrogen radical or dihydrogen, respectively. Here, M refers to the molecular mass of the compound. In the spectrum for toluene, a hydrogen radical (proton-electron pair) is lost, forming the M-1 (91) peak.
Electron affinity can be defined in two equivalent ways. First, as the energy that is released by adding an electron to an isolated gaseous atom. The second (reverse) definition is that electron affinity is the energy required to remove an electron from a singly charged gaseous negative ion.
It is a hard, slightly malleable, silvery metal that quickly tarnishes in air and moisture. When oxidized, neodymium reacts quickly producing pink, purple/blue and yellow compounds in the +2, +3 and +4 oxidation states. It is generally regarded as having one of the most complex spectra of the elements. [9]