Helion (chemistry)

Helium-3 isotope nucleus

For other uses, see Helion (disambiguation).

A helion (symbol h) is the nucleus of a helium atom, a doubly positively charged cation. The term helion is a portmanteau of helium and ion, and in practice refers specifically to the nucleus of the helium-3 isotope, consisting of two protons and one neutron. The nucleus of the other (and far more common) stable isotope of helium, helium-4, consisting of two protons and two neutrons, is called an alpha particle or an alpha for short.

This particle is the daughter product in the beta-minus decay of tritium, an isotope of hydrogen:[citation needed]

| → | 3
2He
| + |

| + |

|
|
|
|
|
|

CODATA reports the mass of a helion particle as mh = 5.0064127862(16)×10−27 kg‍[1] = 3.014932246932(74) Da.[2]

Helions are intermediate products in the proton–proton chain reaction in stellar fusion.

An antihelion is the antiparticle of a helion, consisting of two antiprotons and an antineutron.

## References

[edit]

1. ^ "2022 CODATA Value: helion mass". The NIST Reference on Constants, Units, and Uncertainty. NIST. May 2024. Retrieved 2024-05-18.
2. ^ "2022 CODATA Value: helion mass in u". The NIST Reference on Constants, Units, and Uncertainty. NIST. May 2024. Retrieved 2024-05-18.

This nuclear chemistry–related article is a stub. You can help Wikipedia by expanding it.

|

* v
* t
* e

*[v]: View this template
*[t]: Discuss this template
*[e]: Edit this template