Effective Nuclear Charge

Why is nuclear charge important?

The nucleus is what holds an electron in an atom

* nuclear charge defines how strongly the electron is held by the nucleus

What is an effective nuclear charge?

Trick to simplify interactions between electron and nucleus due to multiple electrons

* net positive charge that an electron in an atom or ion feels from the nucleus

How is the effective nuclear charge calculated?

Z sub off = Z (nuclear charge - # of p) - S (shielding constant - # of core e)

* core e: closer to nucleus
* counteract effect of nucleus (-ve charge)
* valence e: outside and around core
* shielded from nucleus by core e

Effective nuclear energy and core electrons by groups and rows?

Z sub off is same for elements in the same group except noble gases

* 1 -8 skipping transition metal group

\
Core e

* 1st row = 0
* 2nd row = 2
* 3rd row = 10
* 4th row = 18 until transition metals, 28 past transition metals