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".
Helium-4 - isotopic data and properties - ChemLin
The following table shows the atomic nuclei that are isotonic (same neutron number N = 2) and isobaric (same nucleon number A = 4) with Helium-4. Naturally occurring isotopes are marked in green; light green = naturally occurring radionuclides.
Isotopes of helium - Wikipedia
Isotopes of helium. 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.
Helium-4 | chemical isotope | Britannica - Encyclopedia Britannica
…protons and one neutron, and helium-4 (or 4 He), with two protons and two neutrons. 4 He forms the bulk of naturally occurring helium, but the lighter isotope 3 He has been formed, since about 1950, in experimentally useful quantities by the decay of …
Helium-4 - Simple English Wikipedia, the free encyclopedia
Helium-4 (also written 4 He) is an isotope of helium. It is the most common isotope of helium in the universe. Out of all the helium on the Earth, 99.99986% is helium-4. The nucleus (the center) of a helium-4 atom is also known as the alpha particle.
Helium-4 atom | He | CID 5460511 - PubChem
2021年5月7日 · 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.
Helium | Definition, Properties, Uses, & Facts | Britannica
2024年10月25日 · Helium-4 is by far the most plentiful of the stable isotopes: helium-4 atoms outnumber those of helium-3 about 700,000:1 in atmospheric helium and about 7,000,000:1 in certain helium-bearing minerals.
Helium - Wikipedia
The most common isotope of helium in the universe is helium-4, the vast majority of which was formed during the Big Bang. Large amounts of new helium are created by nuclear fusion of hydrogen in stars.
Helium-4 - Wikiwand
Helium-4 (4. He. ) is a stable isotope of the element helium. It is by far the more abundant of the two naturally occurring isotopes of helium, making up about 99.99986% of the helium on Earth. Its nucleus is identical to an alpha particle, and consists of two protons and two neutrons.
Helium-4 - chemeurope.com
Helium-4 is a non- radioactive and light isotope of helium. It is by far the most abundant of the two naturally-occurring isotopes of helium, making up about 99.99986% of the helium on earth. Its nucleus is a boson and an alpha particle, having two protons and two neutrons.