how long time remaining for the sun fuel to be exhausisted ?

Question

the hydrogen is the fuel for the sun so why it will not ignited in one time

Answer 1

The first part of your question has been answered. The hydrogen will run out in about 5 billion years. For the second part, the sun does not ignite all its hydrogen at once like a bomb because the reaction needs very high pressure and temperatures. Those only exist at the very core of the sun. There is insufficient pressure elsewhere for it to take place.

Answer 2

Yes about five billion years. But I do disagree with the inner planets being consumed by the sun. I have seen thoughts and calculations that by the time that happens the sun will have lost enough mass that the earth at least will be far enough away from the sun as not to be engulfed. Of course it will get a bit toasty. But by that time I am sure that we will have some very good A/C in our homes.
B

Answer 3

After hydrogen is exhausted, the sun used helium. Our sun has about 5 billion years to burn before it expands to a red giant, consuming all of the inner planets.

Answer 4

Long enough for me!
Read on:

Answer 5

5 billion years, and then you can kiss your rear good bye.