Question

If oxygen is required for combustion then , how is sun burning in the space??

Answer 1

Actually, Sun is not burning by any means. We learnt in childhood, “Sun is a burning ball of hot gas”. It’s not true, Sun is neither a fire too.  A fire is a result of combustion process (Something combines with oxygen to produce heat.  Now, how does Sun gets so much energy, if it’s not burning?  Actually fusion reaction takes place. In this process, atoms of hydrogen are converted to helium.   When protons interact at low temperatures and low velocities, two protons are repulsed from one another by electromagnetic force but at high temperatures and velocities, protons undergo fusion resulting to the nuclear fusion process by combining smaller nuclei into heavier ones and continuously releasing large amounts of energy.  After converting hydrogen to helium, it emits lots of energy which fuels the sun.   The sun is not a chemical process, It is a nuclear process.  As we know, A nuclear power plant does not need oxygen because it uses a nuclear reaction to make heat. There's no fire in a nuclear reactor. The same happens in a nuclear fusion process of Sun.  The “fire” of the sun is not due to combustion but due to nuclear fusion, which does not need any oxygen to work.  So don’t confuse that, Sun is a burning ball. In fact, it is not.

Answer 2

so sun can burn hydrogen to helium without need of oxygen it should be noted in presence of carbon nitrogen and oxygen stars are heavier than the sun may burn hydrogen to helium by using the carbon nitrogen and oxygen as catalysts in combustion reactions oxygen occurs