Do Some Stars Fuse Hydrogen And Helium Simultaneously?

Question

If So What Other Elements Do They Fuse At The Same Time

Answer 1

Yes. After they evolve off the main sequence, stars may be burning helium in the core and hydrogen in a shell around the core; or hydrogen and helium in concentric shells around a carbon-oxygen core. Beyond helium, the main fusion reactions are carbon/oxygen to magnesium and neon, Mg/Ne to silicon and sulfur, and Si/S to iron. Massive stars can have multiple shells active simultaneously.

Answer 2

Not usually, because stars burn their hydrogen and convert it into Helium. When the hydrogen supply is used up, then the star is at the end of it's life. Then comes the stars demise, to a white dwarf, or supernova. For instance, our sun can't burn the helium it creates, it burns the hydrogen.