The correct statement regarding nuclear fusion is:
The product has more mass than the reactants because some mass is converted into energy.
In nuclear fusion, lighter atomic nuclei combine to form a heavier nucleus, and during this process, a small amount of mass is converted into energy, according to Einstein's equation \(E=mc^2\). Thus, while the mass of the product is actually less than the total mass of the reactants, the statement needs to be interpreted carefully, as the energy released can be related to the mass lost.
If you're specifically looking for the correct reasoning behind why fusion releases energy, it's because the binding energy of the produced nucleus is greater than that of the individual reactants, resulting in a release of energy.
So to summarize:
- The number of particles in the product is generally not greater than the number of reactants; it's often fewer.
- The product can often be found in nature (for instance, helium).
- The atomic number of the product is indeed the sum of the atomic numbers of the reactants.
- The statement about mass and energy has subtlety but could be misleading; the correct aspect is that energy is released during the conversion of mass.
Given the options you proposed, the most correct is the one about atomic numbers.