Question

How were the heavy elements from iron to uranium made?

Answer 1

The elements formed in these stages range from oxygen through to iron. During a supernova, the star releases very large amounts of energy as well as neutrons, which allows elements heavier than iron, such as uranium and gold, to be produced. In the supernova explosion, all of these elements are expelled out into space.

Answer 2

stars release energy mostly produced by hydrogen fusing into Helium. As a star becomes older there is less hydrogen so it starts fusing heavier elements. But each time you move along the periodic table less energy is produced