Chemistry
Effective Nuclear Charge Calculator
Calculate the effective nuclear charge felt by an electron from the atomic number and the shielding constant.
Your inputs
Change any value to update the result instantly.
Effective nuclear charge (Z_eff)
2.2
Nuclear charge (Z)
11
Shielding (S)
8.8
Fraction of nuclear charge felt
20 %
Calculate S with Slater's rules for the electron you are studying. A larger Z_eff means the electron is held more tightly.
What this calculator does
Calculates the effective nuclear charge experienced by an electron once inner-electron shielding is subtracted.
What your result means
Z_eff is the net positive charge felt by the chosen electron; larger values mean tighter binding and smaller atomic radius.
Formula and working
Z_eff = Z − S
- 1
Collect the inputs
Atomic number (Z) = 11; Shielding constant (S) = 8.8
- 2
Apply the formula
Z_eff = Z − S
- 3
Result
Effective nuclear charge (Z_eff) = 2.2
Frequently asked questions
Symbols and assumptions
- Z
- Atomic number
- S
- Shielding (screening) constant
- Z_eff
- Z − S
- • The shielding constant S is supplied by the user, normally from Slater's rules.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • Slater's rules are an approximation; self-consistent-field values differ, especially for d and f electrons.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
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