Which of the following statements is always true for neutron-induced fission reactions involving 235,92U?
Deal with nuclear fission for which the following reaction is a good example.
23592U + 10n → 13856Ba + 9536Kr + neutrons + released energy
Which of the following statements is always true for neutron-induced fission reactions involving 23592U?
I. The end products always include Ba and Kr.
II. The rest mass of the end products is less than that of 23592U + 10n.
III. The total number of nucleons (protons plus neutrons) in the end products is less than that in 23592U + 10n.
(A) II only
(B) III only
(C) I and II only
(D) I and III only
(E) I, II, and III
1 Answers
The correct option is: (A) II only
Explanation:
I. is Not True, for the following reason:
In fission, and U–235 nucleus is broken into fragments that make smaller elements + neutrons + energy. The fragments created are not always the same and there is a statistical probability of which fragments can be created. The reaction provided in this problem is the most probable but other elements can be formed such as the following U–235 fission reaction: U-235 + n → Zr-94 + Te-139 + 3n + energy. There are actually many combinations of fragments that can be released. Small amounts of mass are missing as released energy but adding the whole numbers of the reaction will always balance the equation for a given reaction.
II. is TRUE. As explained above, as small amount of the mass will be missing in the form of energy after the reaction completes. This is necessary to produce the energy from the reaction.
III. is Not True. Again as explained in the first paragraph. There will be a small amount of mass missing but adding the whole numbers before and after will always result in the same numbers of particles for a fission reaction.