Question

which quantity is the same before and after a nuclear change? (1 point)
○ total mass
○ atomic number of each atom
○ total charge
○ atomic mass of each atom
check answer remaining attempts : 3

Explanation:

• Total mass: In nuclear changes (like fission or fusion), mass can be converted into energy (as per \(E = mc^{2}\)), so total mass is not conserved.
• Atomic number of each atom: In nuclear reactions (e.g., alpha decay where \(_{Z}^{A}X

ightarrow_{Z - 2}^{A-4}Y+_{2}^{4}He\)), the atomic number (\(Z\)) of the parent atom changes.

• Total charge: According to the law of conservation of charge, the total charge before and after a nuclear change remains the same. In any nuclear reaction (whether it is radioactive decay, fission, or fusion), the sum of the charges of the reactant nuclei and particles is equal to the sum of the charges of the product nuclei and particles.
• Atomic mass of each atom: Atomic mass (\(A\)) can change. For example, in beta - minus decay \(_{Z}^{A}X

ightarrow_{Z + 1}^{A}Y+_{-1}^{0}\beta\), although \(A\) (atomic mass number) may stay the same in some decays, in fission (\(_{92}^{235}U+_{0}^{1}n
ightarrow _{56}^{141}Ba + _{36}^{92}Kr+3_{0}^{1}n\)) the atomic mass of the parent atom (\(U - 235\)) is different from the atomic masses of the product atoms (\(Ba - 141\) and \(Kr - 92\)).

Answer:

total charge