Sun is ball of buring fire. To burn something we need oxygen. Then from where does oxygen come from in space???

In side the sun , the process of nuclear fusion takes place which is a totally different process. Hydrogen and helium are the main elements present in sun.

The nuclear reactions which take place in the sun are the nuclear fusion .

Nuclear Fusion reactions are those reactions in which two small nuclei fuse together to form a bigger nucleus, with evolution of large amount of energy (almost three to four times greater than nuclear fission reaction). These type of reactions occur in the Sun and are responsible for the heat energy of the Sun. These reactions require very high temperatures.

So, basically there is a nuclear fusion reaction taking place in the core of the sun . In it four hydrogen atoms combine to form helium atom . It emits a very large amount of heat and light energy . This reaction takes place at a very high temperature .

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