Effective nuclear charge can be calculated by using the formula:

• A. Z* = Z - S
• B. Z* = Z + S
• C. Z* = S - Z
• D. Z = Z* - S

The effective nuclear charge (Z*) is a concept used to describe the net positive charge experienced by an electron in an atom. It takes into account the actual nuclear charge (Z) and the shielding effect of other electrons (S). The correct formula to calculate the effective nuclear charge is:

Correct Formula

Z* = Z - S

Explanation of Terms

• Z: The total number of protons in the nucleus, representing the atomic number.
• S: The shielding constant, which accounts for the repulsion from other electrons that reduces the full nuclear charge felt by an electron.
• Z*: The effective nuclear charge, indicating how strongly an electron is attracted to the nucleus.

By using this formula, you can determine how effectively the nucleus can attract electrons, which is crucial for understanding atomic behavior and chemical properties.