Which statement is balanced equations for nuclear and chemical changes is correct?
A. A nuclear equation is balanced according to mass number. A chemical equation is balanced according to the total before and after the change.
B. Both are balanced according to the mass number of each element before and after the change.
C. A chemical equation is balanced according to mass number. A nuclear equation is balanced according to the total mass before and after the change.
D. Both are balanced according to the total mass before and after the change.
C. A chemical equation is balanced according to mass number. A nuclear equation is balanced according to the total mass before and after the change.
The correct statement is C. A chemical equation is balanced according to mass number. A nuclear equation is balanced according to the total mass before and after the change.
The correct statement is C. A chemical equation is balanced according to the mass number. A nuclear equation is balanced according to the total mass before and after the change.
To understand why this statement is correct, let's break it down:
A chemical equation represents a chemical change, where atoms of different elements rearrange to form new substances. When balancing a chemical equation, we ensure that the number of each type of atom is the same on both sides of the equation. This is done by adjusting the coefficients in front of each reactant and product.
In a chemical equation, the number of atoms must be balanced, but the total mass before and after the change is also conserved. This means the total mass of the reactants should be equal to the total mass of the products.
On the other hand, a nuclear equation represents a nuclear change, such as radioactive decay or nuclear fusion. In a nuclear equation, the reactants and products are different isotopes or particles, and their mass numbers are considered. A nuclear equation is balanced by ensuring that the sum of the mass numbers of the reactants equals the sum of the mass numbers of the products.
So, in summary, a chemical equation is balanced according to mass number, and a nuclear equation is balanced according to the total mass before and after the change. Therefore, option C is the correct statement.