•Chapter 7: The
 Sun – example question
 •Q. The fusion
 process in the sun, the "proton-proton" chain, requires high temperatures because:
 •c of the ground-state energy of the Hydrogen atom.
 •c of the presence of Helium atoms.
 •c the colliding protons need high energy to overcome
 the Coulomb barrier.
 •c of the need for low density.
 •c the
 neutrinos carry more energy away than the reaction produces.