What is the heaviest element that stars can produce through fusion?

What is the heaviest element that stars can produce through fusion?

• A. Hydrogen
• B. Oxygen
• C. Iron
• D. Helium

Answer: (C)

Stars fuse light nuclei step by step, releasing energy along the way. The energy released per nucleon increases as you fuse up to iron, because iron-56 sits at the peak of the binding-energy curve. Fusing nuclei beyond iron would require energy input rather than deliver energy, so the star’s hydrostatic fusion can’t efficiently build heavier elements in its core. Heavier elements are then formed mainly during explosive events, like supernovae, through neutron capture rather than steady fusion. So the heaviest element that stars can produce through fusion in their normal burning stages is iron. Hydrogen, helium, and oxygen are produced earlier in the life of a star, but iron is the heaviest produced by fusion in hydrostatic burning.

Stars fuse light nuclei step by step, releasing energy along the way. The energy released per nucleon increases as you fuse up to iron, because iron-56 sits at the peak of the binding-energy curve. Fusing nuclei beyond iron would require energy input rather than deliver energy, so the star’s hydrostatic fusion can’t efficiently build heavier elements in its core. Heavier elements are then formed mainly during explosive events, like supernovae, through neutron capture rather than steady fusion.

So the heaviest element that stars can produce through fusion in their normal burning stages is iron. Hydrogen, helium, and oxygen are produced earlier in the life of a star, but iron is the heaviest produced by fusion in hydrostatic burning.