Which of the following is generally true regarding effective nuclear charge `(Z_(eff))`:

Options

A. It increases on moving left to right in a period.
B. It remains almost constant on moving top to bottom in a group.
C. For isoelectronic species, as `Z` increases, `Z_(eff)` decreases.
D. Both `(A)` and `(B)`

Answer

D

Explanation

For isoelectronic species, as `Z` increases, `Z_(eff)` increases (and vice versa).