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mass of helium atom in kilograms - Wolfram|Alpha Wolfram|Alpha brings expert-level knowledge and capabilities to the broadest possible range of people—spanning all professions and education levels.
Helium – Atomic Mass – Atomic Weight – He - Periodic Table of ... 21 Nov 2020 · Helium - Atomic Mass - Atomic Weight - He. The Helium atomic mass is the mass of an atom. The density of a substance strongly depends on its atomic mass and also on the atomic number density.
Isotopes of helium - Wikipedia Helium (2 He) (standard atomic weight: 4.002 602(2)) has nine known isotopes, but only helium-3 (3 He) and helium-4 (4 He) are stable. [4] All radioisotopes are short-lived; the longest-lived is 6 He with half-life 806.92 (24) milliseconds. The least stable is 10 He, with half-life 260 (40) yoctoseconds (2.6 (4) × 10−22 s), though 2 He may have an even shorter half-life. In Earth's ...
Helium-4 atom | He | CID 5460511 - PubChem 7 May 2021 · Helium-4 atom is the stable isotope of helium with relative atomic mass 4.002603. The most abundant (99.99 atom percent) isotope of naturally occurring helium. It contains an alpha-particle.
He{4-} Molar Mass - ChemicalAid The molar mass and molecular weight of He{4-} is 4.005.
Helium-4 - Wikipedia Helium-4 makes up about one quarter of the ordinary matter in the universe by mass, with almost all of the rest being hydrogen. While nuclear fusion in stars also produces helium-4, most of the helium-4 in the Sun and in the universe is thought to have been produced during the Big Bang, known as " primordial helium".
CHEBI:30219 - helium-4 atom - EMBL-EBI The stable isotope of helium with relative atomic mass 4.002603. The most abundant (99.99 atom percent) isotope of naturally occurring helium. Stars
Helium Isotopes - List and Properties - ChemLin Eight isotopes are known for the lightest noble gas, helium, of which only two are stable: 3 He and 4 He occur in nature as an isotope mixture in a ratio of approx. 1:1,000,000 on. This results in a relative atomic mass for helium of 4.002602 (2) u on average. The isotopic composition in nature is subject to large fluctuations and is strongly dependent on the presence of 3 H sources. …
Helium-4 - isotopic data and properties - ChemLin Name of the isotope: Helium-4; He-4 Symbol: 4 He or 42 He Mass number A: 4 (= number of nucleons) Atomic number Z: 2 (= number of protons) Neutrons N: 2 Isotopic mass: 4.0026032541 (4) u (atomic weight of Helium-4) Nuclide mass: 4.0015061 u (calculated nuclear mass without electrons) Mass excess: 2.42492 MeV Mass defect: 0.0303766419 u (per ...
Helium-4 - Simple English Wikipedia, the free encyclopedia Helium-4 on Earth was made through radioactive decay (when an atom breaks down into smaller atoms) from other elements, and it is made after the planet cooled and became solid. One quarter of all the mass in the Universe is helium-4. The rest is mostly hydrogen.