Effective nuclear charge, Zeff

1. Effective nuclear charge
Dr. Mithil Fal Desai
Shree Mallikarjun and Shri Chetan
Manju Desai College Canacona Goa

2. Nuclear Charge
Atom
P
P
PP

3. Effective nuclear charge (Zeff)
Nuclear charge is charge on the
nucleus.
Effective nuclear charge is the
nuclear charge actually experienced
by an electron of an atom.
.

4. Effective nuclear charge (Zeff)
Nucleus
e-
Depends on ‘n’ and ‘l’

5. Atomic number and Nuclear charge (Z)
Orbital 1s 1s 1s, 2s 1s, 2s 1s, 2s, 2p 1s, 2s, 2p 1s, 2s, 2p
n of
valence
shell
1 1 2 2 2 2 2
Z 1 2 3 4 5 6 7
e-ns in
neural
atom
1 2 3 4 5 6 7
Element H He Li Be B C N

6. Zeff = Z – σ
σ is shieling constant
Mathematical expression

7. Factors affecting
• Size of an atom
• The total nuclear charge (Z).
• The Screening and Shielding of the inner shell
electrons and neighboring electrons of the same shell.
• The extent of penetration of outermost electron into
the charge cloud.