The atomic number of an element is equal to the number of protons in the nucleus of an atom of that element. It is represented by the symbol "Z".

To calculate the atomic number of an element:

* Count the number of protons in the nucleus of an atom of that element.

* The number of protons is equal to the atomic number of the element.

For example, the atomic number of carbon is 6. This means that an atom of carbon has 6 protons in its nucleus.