Question

How can an atomic number of electrons be determined?

Answer 1

Your question is ill-proposed. Electrons do not have an atomic number.

Explanation:

Atomic number is an atomic property, i.e. a property of the charged massive particles.

The number of positively charged nuclear particles, protons, is called `Z`, the atomic number.

In the neutral element, with atomic number `Z`, there are also `Z` electrons associated with the element. The number is the same, because if it was not, the element would not be neutral.