Which of the following is closest to the effective nuclear charge (Z_eff) experienced by a 2p electron in a neon atom?

• A. Z_eff ≈ 8.0
• B. Z_eff ≈ 2.0
• C. Z_eff ≈ 5.7
• D. Z_eff ≈ 10.0

Answer: (C)

Verified step by step guidance

1. Identify the atomic number (Z) of neon, which is 10, meaning neon has 10 protons in its nucleus.
2. Recognize that the effective nuclear charge (Z_eff) experienced by an electron is given by the formula: \(Z_{eff} = Z - S\), where \(S\) is the shielding constant representing the extent to which other electrons shield the electron of interest from the full nuclear charge.
3. Determine which electrons contribute to shielding the 2p electron. For a 2p electron in neon, the shielding comes mainly from the 1s electrons and the other electrons in the 2s and 2p orbitals.
4. Estimate the shielding constant \(S\) using Slater's rules or a similar approach: assign shielding values to electrons in different shells and subshells to calculate \(S\) for the 2p electron.
5. Calculate \(Z_{eff}\) by subtracting the shielding constant \(S\) from the atomic number \(Z\): \(Z_{eff} = 10 - S\). This will give the effective nuclear charge experienced by the 2p electron.