What is the most common gases inside the sun?

Answer 1

I'm no astrophysicist (not even a scientist), but I'm assuming the most common gas inside the sun is going to be Hydrogen.

Hydrogen is the most common element in the Universe and gives off a massive amount of energy when fused through nuclear fusion. Most stars are formed by giant clouds of dense hydrogen gas (and dust) that are slowly compacted together by gravity over thousands of years. The more compacted it gets, the higher the temps go, and ultimately at around 15million degrees, nuclear fusion sparks and a star is born.

At the moment of birth, the star blasts a nuclear shockwave out that not only signals its birth, but also serves to blast the remaining matter it did not use in its creation to help form a local system of planets, moons, and asteroids.

Over time, however, the star will burn through its hydrogen and create heavier and heavier elements like helium, oxygen, and carbon. By the time a star like ours begins to fuse carbon, it begins its death cycle, as the next element it tries to make is iron, which gives off no energy when fused and that is when a star either swells into a red giant (like our sun will) or goes supernova (in the case of the really big stars).

So our sun should still contain mostly hydrogen, but in its core it is slowly creating an onion-like structure of heavier and heavier elements as it burns through its fuel.