1. What is Effective Nuclear Charge?

The effective nuclear charge (Z_eff) is the net positive charge experienced by an electron in an atom. It accounts for both the attraction to the nucleus and the repulsion from other electrons.

2. How Does the Calculator Work?

The calculator uses the effective nuclear charge equation:

Where:

• \( Z \) — Atomic number (number of protons)
• \( \sigma \) — Screening constant (shielding effect of other electrons)

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_eff Calculation

Details: Effective nuclear charge helps explain periodic trends like atomic size, ionization energy, and electronegativity. It's crucial for understanding chemical bonding and reactivity.

4. Using the Calculator

Tips: Enter the atomic number (1-118) and the screening constant (typically between 0 and Z-1). The screening constant depends on electron configuration.

5. Frequently Asked Questions (FAQ)

Q1: How do I determine the screening constant?
A: The screening constant can be estimated using Slater's rules or other empirical methods based on electron configuration.

Q2: Why does Z_eff increase across a period?
A: While protons are added, shielding by inner electrons remains relatively constant, resulting in greater effective nuclear charge.

Q3: How does Z_eff affect atomic radius?
A: Higher Z_eff pulls electrons closer to the nucleus, resulting in smaller atomic radius.

Q4: What's the typical range for Z_eff?
A: For valence electrons, Z_eff is typically between +1 and +8 for main group elements.

Q5: Does Z_eff vary for different electrons in the same atom?
A: Yes, inner electrons experience higher Z_eff than outer electrons due to less shielding.