Where does the energy in fusion and fission come from?

 i think that it is When fusion occurs in the sun, its due to quantum tunneling causing hydrogen atoms to bind, forming helium. Energy is released because two hydrogen atoms have more energy then one helium atom, and when they bind the excess is released into space. The energy itself comes from some of the mass deteriorating into photons. i hope i help

When fusion occurs in the sun, its due to quantum tunneling causing hydrogen atoms to bind, forming helium. Energy is released because two hydrogen atoms have more energy then one helium atom, and when they bind the excess is released into space. The energy itself comes from some of the mass deteriorating into photons.