Enter the number of protons in the nucleus and the shielding constant to determine the effective nuclear charge.

Effective Nuclear Charge Formula

The following formula is used to calculate an effective nuclear charge.

Zeff = Z – S

  • Where Zeff is the effective nuclear charge
  • Z is the number of protons in the nucleus
  • S is the shielding constant

Effective Nuclear Charge Definition

An effective nuclear charge is defined as the net positive charge of the valence electrons of an atom.

Effective Nuclear Charge Example

How to calculate effective nuclear charge?

  1. First, determine the number of protons.

    This will also be equal to the atomic number of the atom.

  2. Next, determine the shielding constant.

    Using the number of electron shells, determine the shielding constant.

  3. Finally, calculate the effective nuclear charge.

    Subtract the shielding constant from the number of protons to determine the effective nuclear charge.


What is an effective nuclear charge?

The effective nuclear charge is the net positive charge that valence electrons experience.

What is a shielding constant?

The shielding constant is the difference between the pull on valence electrons due to protons and the push from inner electrons. The more electron shells there are in an atom the greater the shielding effect.