Helium is produced in radioactive process that occurs in deep and underground formations. They differ from other atmospheric gases. These radioactive decay of heavier nuclides that are unstable started about the time when the earth was formed.
As they decay they give off lighter particles that can easily be broken down into more stable ones.
One of the main product of the decay is alpha particles.
They have the same atomic structure as helium
These materials are trapped in underground formations.
