What fuels the sun?

Have you people ever wondered what was the fuel in Sun?
No?
Well, think about it now.


So, what's the answer?
Fusion Reaction.

Stars don't literally burn. So, there's no Oxygen required for combustion.
Hydrogen gas fuses to form helium.Some of the mass is lost which is converted into Energy.
The energy formed when they fuse serves as the fuel for stars.
About 70% of the sun is Hydrogen gas.
Rest is hydrogen converted into helium.
So, the current composition of our Sun is 70% Hydrogen and 30% Helium.

What happens if all of the Hydrogen gas is converted into Helium?
Well, it's obvious, isn't it?
The Sun will run out of fuel.Without fusion reactions, the core of Sun will inflate and then collapse due it's own gravity.The collapse will create enormous amounts of heat.
The Hydrogen present in the outer layers of Sun will react with the supply of the enormous heat energy and fusion starts.
These fusions will thus inflate the Sun causing it to blow up into a Red Giant.

The current diameter of our sun is 0.01 Astronomical Units.
The diameter of the Sun at the Red Giant stage will be about 2 Astronomical Units.
Yep.
Our Sun's size would increase 200 times.