Answer: option D - The total number of nucleons changes.
Explanation:
Nuclear Reaction is best described as a process such as the fission of an atomic nucleus, or the fusion of one or more atomic nuclei and / or subatomic particles in which the NUMBER of PROTONS and / or NEUTRONS in a nucleus CHANGES; the reaction products may contain a different element or a different isotope of the same element.
Note that the NUCLEONS refers to ONE of the subatomic particles of the atomic nucleus, i.e. a PROTON or a NEUTRON.
So, in a Nuclear reaction, the total number of nucleons changes.
The concentration of [CI-] : 0.617 M
<h3>Further explanation</h3>
FeCl₃ dissolved in 450 mL of solution(will dissociate )
Reaction
FeCl₃⇒Fe³⁺+3Cl⁻
- mol FeCl₃(MW=162,2 g/mol)



The true answer is: It's conserved because the total number of H atoms on each side is 12.
the first two answer is wrong because it's conserved not as mentioned, It's not conserved.
and the last one also wrong because the total number of O atoms are equal at the two sides but not equal 2.
True. The building blocks of life are atoms