Rank the effective nuclear charge Z* experienced by a valence electron in each of these atoms: atom Z* experienced by a valence electron.
An atom of carbon.
An atom of fluorine.
An atom of beryllium.
An atom of boron.

The atoms are ranked in decreasing order as follows:

Fluorine ---4

Carbon 3

Boron 2

Beryllium --1

Explanation:

Effective nuclear charge (Zeff) is defined as the difference between the actual nuclear charge (the atomic number, Z) and the shielding constant (S).

It is calculated by finding the atomic number and electronic configuration, attributing a shielding value to each electron, adding all the shielding values and using the formula:

                 Z eff = Z - S

Effective nuclear charges:

An atom of carbon: 3.25

An atom of fluorine: 5.20

An atom of beryllium: 1.95

An atom of boron: 2.60