This preview shows page 1. Sign up to view the full content.
Unformatted text preview: f to predict properties and determine the
amount of energy it takes to remove an electron from its
‘home’. The net positive charge attracting the e- (Zeff) will vary
depending on where the electron is residing.
In general, Zeff can be expressed by:
z actual- electron shielding S.
____________________________________ where Zactual equals the number of protons in the nucleus (and is thus the
charge of the nucleus) and S is the average number of e- b/w the nucleus
and the e- in question.
e.g.,electron 92 in uranium
- 91 electrons r there b/w
nucleus and its outermost
in the diagram we see that
outer electrons are not just
attracted by the nucleus
but also pushed away or under
repulsion by the inner electrons.
this attraction and repulsion
creates a balance. 15 05-Sep-13 Penetration effect
• Describes the proximity of an orbital to the nucleus.
• Electrons in different orbitals have different distributions
around the nucleus.
• Electrons which experience greater penetration experience
less shielding and therefore experience a larger Effective
Nuclear Charge (Zeff).
View Full Document