Where do the sun get the fire

they say that sun is the outcome of nuclear fission of hydrogen and helium gases.
hmm.. where do this hydrogen and helium come from? maybe when our teacher thought this to us, I'm probably not listening.

When the universe formed, and after it cooled enough for real atoms to exist, it consisted of 99% hydrogen.
All the hydrogen atoms found today - in balloons, in your glass of water, and all the oceans - have been around since the birth of the universe.

Today, I believe the amount of matter that makes up the universe is now still more than 90% hydrogen. Clouds of hydrogen drift within the galaxies, and start to condense due to gravity. As the cloud of gas condenses further, the pressure developing within due to gravity begins to heat the core. As more and more hydrogen collects, the core's pressure and heat increases, and finally it reaches the point of nuclear fusion - the hydrogen is being "burned" to form helium. This is the birth of the star.

>>they say that sun is the outcome of nuclear fission of hydrogen and helium gases<<

Not quite - it is fusion of hydrogen into helium.


>>where do this hydrogen and helium come from?<<

Hydrogen, and a little bit of helium, were made by the Big Bang.


The presence of heavy elements in our Sun and Solar System indicate that we were made of the remains of a previous star (which made the heavy elements) that went supernova (otherwise we would not have any elements heavier than iron).

nuclear fission of hydrogen and helium gases

With fission of those nuclei, you actually lose energy, not gain. http://en.wikipedia.org/wiki/Nuclear_fis… For fission you should try heavier elements (the heavier, the better) -- preferably things with atomic number much higher than iron.

If you want to get energy from nuclear reactions involving hydrogen or helium, you should try FUSION instead. http://en.wikipedia.org/wiki/Nuclear_fus…