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 …

Properties and data of the isotope 4 He. See also: list of Helium isotopes. Direct parent isotopes are: 5 He, 5 Li, 6 Be. The following table shows the atomic nuclei that are isotonic (same …

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 …

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 …

…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, …

Superfluid helium-4 (helium II or He-II) is the superfluid form of helium-4, an isotope of the element helium. A superfluid is a state of matter in which matter behaves like a fluid with zero …

Helium-4 (4He) 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 …

Seven isotopes of helium are known: Liquid helium (He-4) exists in two forms: He-4I and He-4II, with a sharp transition point at 2.174K. He-4I (above this temperature) is a normal liquid, but …

Detailed decay information for the isotope helium-4 including decay chains and daughter products.

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 …