During nuclear fusion in a red giant star, when a hydrogen atom with 1 proton is fused with a nitrogen atom with 7 protons, what will the resulting atom be?
Nitrogen and hydrogen fuse to form oxygen.
In a large star the main process of fusing hydrogen into helium is the CNO cycle. This process involves various isotopes of carbon, nitrogen and oxygen fusing with hydrogen to form other carbon, nitrogen and oxygen isotopes and ultimately helium.
The fusion of nitrogen and hydrogen occurs twice in the cycle, each involving a different isotope of nitrogen.
The first one involves fusing nitrogen 14 with hydrogen to form oxygen 15:
The second is the final process of fusing nitrogen 15 with hydrogen to form carbon 12 and helium 4: