What is the heat source in the Earth’s core?

Question

I understand that the Earth’s core is full of very hot liquid rock, but why is it hot and why does it stay hot?

What is the heat source?

In: Planetary Science

Answer 1

There are four sources for heat at the Earth’s core

1 – Latent heat remaining from the formation of the earth.

2 – Radioactive decay of elements, which BTW is also the source of most helium found on Earth.

3 – Crystallization of iron in the Earths core releases heat.

4 – Heavier elements slowly sinking to the core converts potential energy into heat.