enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Helium hydride ion - Wikipedia

    en.wikipedia.org/wiki/Helium_hydride_ion

    The helium hydride ion, hydridohelium(1+) ion, or helonium is a cation (positively charged ion) with chemical formula HeH +. It consists of a helium atom bonded to a hydrogen atom, with one electron removed. It can also be viewed as protonated helium. It is the lightest heteronuclear ion, and is believed to be the first compound formed in the ...

  3. Helium compounds - Wikipedia

    en.wikipedia.org/wiki/Helium_compounds

    It was the first known triatomic helium van der Waals molecule. It can be detected by fluorescence. HeI 2 has a similar optical spectrum to I 2, except that the bands and lines are shifted to form two extra series. One series is blueshifted by between 2.4 and 4.0 cm −1, and the other between 9.4 and 9.9 cm −1. The two series may be due to ...

  4. Noble gas - Wikipedia

    en.wikipedia.org/wiki/Noble_gas

    The simplest is the helium hydride molecular ion, HeH +, discovered in 1925. [59] Because it is composed of the two most abundant elements in the universe, hydrogen and helium, it was believed to occur naturally in the interstellar medium, and it was finally detected in April 2019 using the airborne SOFIA telescope.

  5. List of interstellar and circumstellar molecules - Wikipedia

    en.wikipedia.org/wiki/List_of_interstellar_and...

    Designations (names of molecules) are those used in the scientific literature describing the detection; if none was given that field is left empty. Mass is listed in atomic mass units. Deuterated molecules, which contain at least one deuterium (2 H) atom, have slightly different masses and are listed in a separate table. The total number of ...

  6. List of chemical elements - Wikipedia

    en.wikipedia.org/wiki/List_of_chemical_elements

    A chemical element, often simply called an element, is a type of atom which has a specific number of protons in its atomic nucleus (i.e., a specific atomic number, or Z). [ 1 ] The definitive visualisation of all 118 elements is the periodic table of the elements , whose history along the principles of the periodic law was one of the founding ...

  7. Molecules in stars - Wikipedia

    en.wikipedia.org/wiki/Molecules_in_stars

    But certain environments, such as high temperatures, don't allow atoms to form molecules, as the environmental energy exceeds that of the dissociation energy of the bonds within the molecule. Stars have very high temperatures, primarily in their interior, and therefore there are few molecules formed in stars.

  8. Helium atom - Wikipedia

    en.wikipedia.org/wiki/Helium_atom

    A helium atom is an atom of the chemical element helium. Helium is composed of two electrons bound by the electromagnetic force to a nucleus containing two protons along with two neutrons, depending on the isotope , held together by the strong force .

  9. Atomicity (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Atomicity_(chemistry)

    Atomicity is the total number of atoms present in a molecule of an element. For example, each molecule of oxygen (O 2) is composed of two oxygen atoms. Therefore, the atomicity of oxygen is 2. [1] In older contexts, atomicity is sometimes equivalent to valency. Some authors also use the term to refer to the maximum number of valencies observed ...