Question

to find the number of neutrons in an atom, simply calculate: select the correct answer below: atomic number - mass number mass number - atomic number mass number/atomic number atomic number x mass number

Explanation:

Step1: Recall atomic structure

The mass number ($A$) of an atom is the sum of protons and neutrons, and the atomic number ($Z$) is the number of protons. Mathematically, $A =$ number of protons+number of neutrons, and $Z=$ number of protons.

Step2: Solve for number of neutrons

Let the number of neutrons be $N$. Then $A=Z + N$. Rearranging the formula to solve for $N$, we get $N=A - Z$. So the number of neutrons is mass number - atomic number.

Answer:

mass number - atomic number