1. What is Z Effective?

Z effective (Z_eff) is the net positive charge experienced by an electron in an atom. It accounts for both the nuclear charge and the shielding effect of other electrons.

2. How Does the Calculator Work?

The calculator uses the Z effective equation:

Where:

• \( Z \) — Atomic number (number of protons)
• \( \sigma \) — Shielding constant (dimensionless)

Explanation: The equation shows that the effective nuclear charge is the actual nuclear charge reduced by the shielding effect of inner electrons.

3. Importance of Z Effective

Details: Z effective helps explain periodic trends like atomic size, ionization energy, and electronegativity. Higher Z_eff means electrons are held more tightly.

4. Using the Calculator

Tips: Enter the atomic number (1-118) and shielding constant (typically between 0-35). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: How is shielding constant determined?
A: It's calculated using Slater's rules or measured experimentally from spectral data.

Q2: What are typical Z_eff values?
A: For valence electrons, Z_eff ranges from +1 to +8 across the periodic table.

Q3: Why does Z_eff increase across a period?
A: Because added electrons don't shield each other effectively in the same shell.

Q4: How does Z_eff affect atomic radius?
A: Higher Z_eff pulls electrons closer, decreasing atomic radius.

Q5: Is Z_eff the same for all electrons in an atom?
A: No, inner electrons experience higher Z_eff than outer electrons.