RE: Helium 1 rush3 Feb 2024 18:53
Worth an internet search but this may help your question:
There are two stable isotopes of helium: ubiquitous helium-4, which constitutes 99.999% of helium gas, and rare helium-3. Helium-3 is used in neutron detectors and is also a candidate fuel for power generation though nuclear fusion. It is often referred to as “primordial helium”, since the bulk of it was trapped in the Earth’s mantle during the planet’s formation. The more common isotope, helium-4, is mainly produced by the alpha decay of uranium-235, uranium-238 and thorium-232 in the Earth’s crust, which has led to it being called “radiogenic helium”.