Question

How to calculate the number of electrons?

Answer 1

Atoms

• Atoms are the smallest individual part of the matter.
• It consists of electrons, protons, and neutrons.

Electrons

• An electron is a negatively charged subatomic particle.
• Electrons in an atom exist in spherical shells of different radii.
• Mass of an electron: $9.1093837015\times {10}^{-31}\mathrm{kg}$.
• Charge on the electron is $-1.602176634\times {10}^{-19}\mathrm{C}$.

In an atom:

• The number of electrons in a neutral atom is equal to the number of protons.

• The number of protons in the nucleus of the atom is equal to the atomic number (Z).

Therefore, the number of electrons in an atom is equal to the atomic number of an element, for neutrally charged species.