Question

if their is oxygen the fire burns . but in space in space their is no space how would sun is burning

Answer 1

sun has its own heat and light because inside sun many elements persent..which react

Answer 2

It should be noted that in the presence of carbon, nitrogen and oxygen, stars heavier than the Sun may burn hydrogen to helium by using the C, N and O as catalysts. Even in these stars, however, an absence of oxygen does not prevent nuclear burning. First, it isn't a “burning ball of fire.”