In: Physics
The atomic weights of Al28, Fe56 and Cd112 (those are Aluminum, Iron and Cadmium) are 27.982, 55.935 and 111.903 atomic mass units (amu), respectively. Imagine fusing two of these Al nuclei to form one Fe nucleus. Then, imagine fusing two of these Fe nuclei to make one Cd nucleus.
a) What are the mass differences between the input nuclei and the output nucleus in the two cases described? Provide your answer in amu and g. Be consistent about signs!
b) Which of these two reactions is exothermic (produces energy) and which endothermic (consumes energy)?
c) Given what you observe from these comparisons, explain under what conditions Fe and Cd might be able to form in stars