Question

How are protons and neutrons conserved as a star ages?

Answer 1

Once the universe was created by the Big Bang, the only abundant elements present were hydrogen (H) and helium (He). ... The conditions inside a star that allow the formation of the higher mass elements can be related to a pushing match between gravity and the energy released by the star.

Answer 2

Students identify that atoms are not conserved in nuclear fusion, but the total number of protons plus neutrons is conserved. ... Helium and a small amount of other light nuclei (i.e., up to lithium) were formed from high-energy collisions starting from protons and neutrons in the early universe before any stars existed.