Estimate Zeff using Z − S; enter atomic number and shielding constant.
Effective Nuclear Charge (Zeff)
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Formula: Zeff = Z − S
Effective nuclear charge is a simplified way to estimate the net attraction an electron experiences from the nucleus after accounting for shielding by inner electrons. It helps explain periodic trends such as atomic radius and ionization energy.
Effective nuclear charge is the net positive charge felt by an electron after accounting for shielding by other electrons.
Rules like Slater's provide approximate shielding constants; this tool accepts a user-specified S.
Zeff is a dimensionless effective charge (number).
Zeff helps explain trends in atomic radius, ionization energy, and electron affinity across the periodic table.
A shielding larger than Z yields a negative Zeff — unusual in physical contexts and indicates input review is needed.
Yes — compute S via Slater's method externally and enter the value here.
Zeff is an approximation; quantum calculations provide more accurate effective potentials.
Use consistent electron counts and check for typos — Zeff depends on correct inputs.
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