Which internal heat source still generates heat within the terrestrial worlds today?

Question

Quizplus · Accepted Answer

The only internal heat source that still generates heat within the terrestrial worlds today is heat from radioactive decay, where unstable isotopes decay and release energy in the form of heat. The other options (heat of accretion, heat from differentiation, and heat from convection) do not continue to generate heat at a significant level within the current state of the terrestrial worlds.

Which Internal Heat Source Still Generates Heat Within the Terrestrial