Nuclear fusion in the sun involves hydrogen (H) atoms combining to form helium (He). A student claims that since the atmosphere contains hydrogen, any fusion reaction on Earth would result in an uncontrolled chain reaction. What is wrong with the student's reasoning?

Question

supernova_sonntag · Answer

Well, I would assume it is incorrect due to the fact that the Earth is not nearly hot enough, and does not exert enough pressure on H atoms for such a reaction to even occur.

anonymous · Answer

Hydrogen atoms bond together when the energy is so high that when they collide they become subject to a force called the nuclear strong force. This releases Huge amounts of energy (as E=mc^2) states (A little bit of matter is worth a HUGE amount of energy - mass X the speed of light squared!!!).

The reason this is false, is because for the hydrogen atoms to bond and form a chain reaction the energies around them would have to be about as much as we find in the interior of stars, where these reactions take place and this is just not the case on Earth.

Also, in the interior of stars, helium can bond together to form lithium, and lithium into beryllium etc.

All of the atoms in the universe heavier than that of Hydrogen were formed in the interior of stars (all the way up until Iron). All the atoms heavier than Iron were formed in Supernova explosions! 

I hope this helps!