अणु भार कैलकुलेटर — सूत्र

Effective Nuclear Charge

Formula

Z_eff = Z − σ

Where:

Z_eff = effective nuclear charge felt by valence electron

Z = atomic number (total protons)

σ = shielding constant (from Slater's rules)

Inner electrons shield outer electrons from the full nuclear charge. Z_eff increases across a period (more protons, similar shielding) and stays roughly constant down a group.