Final answer:
a) The charge experienced by an electron
The effective nuclear charge (Zeff) is the charge experienced by an electron in an atom. It takes into account the attraction between the nucleus and the electron, as well as any shielding effect from other electrons.
Step-by-step explanation:
The effective nuclear charge (Zeff) is the charge experienced by an electron in an atom. It takes into account the attraction between the nucleus and the electron, as well as any shielding effect from other electrons. Zeff is calculated by subtracting the magnitude of shielding from the total nuclear charge.
For atoms with more than one electron, the inner electrons partially shield the outer electrons from the pull of the nucleus. The effective nuclear charge, Zeff, is equal to the nuclear charge (Z) minus the shielding effect.
The effective nuclear charge, Zeff, plays a role in determining the atomic radius and the chemical properties of an element.