Question

If you are given only the mass number of neutrons, how do we find an atomic number?

Answer 1

You can find the atomic number by subtracting the atomic mass by the number of neutrons.

Answer 2

Mass number is the sum of protons and neutrons.

Atomic number is the total number of protons present.

Mass number = protons + neutrons

Atomic number = protons present.

From the above equations we can conclude that,

Atomic number= Mass number- neutrons.

Thus we can find out the atomic number by subtracting the number of neutrons from the mass number.