Search results
Results from the WOW.Com Content Network
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 ...
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 ...
The unusual stability of the helium-4 nucleus is also important cosmologically: it explains the fact that in the first few minutes after the Big Bang, as the "soup" of free protons and neutrons which had initially been created in about 6:1 ratio cooled to the point that nuclear binding was possible, almost all first compound atomic nuclei to ...
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 .
2 He is an intermediate in the first step of the proton–proton chain. The first step of the proton-proton chain is a two-stage process: first, two protons fuse to form a diproton: 1 H + 1 H + 1.25 MeV → 2 He; then the diproton immediately beta-plus decays into deuterium: 2 He → 2 H + e + + ν e + 1.67 MeV; with the overall formula
This is a good approximation because the nuclei (proton, deuteron or triton) are more than a factor 1000 heavier than the electron. Therefore, the motion of the electron is treated first, for a given (arbitrary) nucleus-nucleus distance R. The electronic energy of the molecule E is computed and the computation is repeated for different values of R.
Helium, oxygen, neon, iron—they all come from the fusion that takes place in dying stars. But we have a lot of elements that are more massive than iron ; it’s only element 26 of 118, after all.
Argonium (also called the argon hydride cation, the hydridoargon(1+) ion, or protonated argon; chemical formula ArH +) is a cation combining a proton and an argon atom. It can be made in an electric discharge , and was the first noble gas molecular ion to be found in interstellar space.