How do you calculate the number of neutrons in an atom?

To determine the number of neutrons in an atom, you subtract the atomic number from the atomic mass. The atomic number represents the number of protons in the nucleus of the atom, while the atomic mass (more accurately, the mass number) is the total number of protons and neutrons contained in the nucleus.

By using the formula of atomic mass minus atomic number, you correctly find the number of neutrons because the mass number accounts for both protons and neutrons, and by removing the count of protons (the atomic number), you are left with the count of neutrons.

This understanding emphasizes the difference between protons and neutrons, as well as the significance of both numbers in the properties of elements.