Question

What are the sources Earth's Internal Heat?​

Answer 1

Radioactivity, the energy produced when unstable atoms decay, is a primary source of heat on Earth. The principal source is the radioactive isotopes uranium-235 (235U), uranium-238 (238U), potassium-40 (40K), and thorium-232 (232Th) found in Earth's mantle.

Apart from heat created during the planet's creation, radioactive potassium, uranium, and thorium are assumed to be the three primary sources of heat in the Earth's interior.

Radioactive decay is the method through which the Earth generates heat. It entails the internal breakdown of naturally radioactive materials such as uranium. Uranium is a unique element in that it produces heat when it decays. This heat is what prevents the Earth from cooling fully.