Which produces more energy:

The fissioning of a single uranium nucleus or the fusing of a pair of deuterium nuclei?

The fissioning of a gram of uranium or the fusing of a gram of deuterium?

a) uranium

b) deuterium

Explanation:

For the first question, you can actually know this by simple logic. The nucleus of Ucranium, has more energy than a pair of deuterium. Ucranium has a mass number and atomic mass higher than deuterium, therefore, when you do a fission with ucranium in it's nucleous, this would be in energy higher than the deuterium.

However, in terms of mass only, the fissioning of 1 gram of Deuterium will produce more energy than 1 gram of uranium, basically because deuterium is lighter and has a lower molecular weight than ucranium. This means that because of this lower molecular weight, in 1 gram of deuterium will contain more number of atoms than in 1 g of uranium. The interaction with these atoms, will produce more energy than the energy produced by uranium.