A particular nuclear reaction has Q=−3.2MeV. What does the negative sign indicate?
a) Energy is absorbed; the reaction is endothermic.
b) Energy is released; the reaction is exothermic.
c) The products are lighter than the reactants by 3.2MeV/c2; the missing mass shows up as kinetic energy of the fragments.
d) Energy conservation requires a 3.2MeVγ-ray to be emitted along with the products.