## Effective Nuclear Charge

TiffanyL1G
Posts: 61
Joined: Fri Sep 28, 2018 12:22 am

### Effective Nuclear Charge

What exactly is Z and how does it come into play for the effective nuclear charge? The equation given is En= - Z^2 eff hR/n^2, can someone explain what this equation is used for and what it means?

Tarika Gujral 1K
Posts: 62
Joined: Fri Sep 28, 2018 12:27 am

### Re: Effective Nuclear Charge

Nuclear charge refers to the strength of nuclear pull on electrons of an atom. However, the presence of more electrons creates shielding, which lowers the nuclear pull. Z-eff refers to the value of nuclear charge - shielding.

Posts: 30
Joined: Fri Sep 28, 2018 12:25 am

### Re: Effective Nuclear Charge

The Z-eff tends to increase as one moves from left to right on the periodic table

Dina Geotas 4A
Posts: 61
Joined: Fri Sep 28, 2018 12:29 am

### Re: Effective Nuclear Charge

Zeff is the effective nuclear charge of an electron. It can be calculated with Zeff= Z-S where Z is the number of protons in the nucleus and S is the electron density between the nucleus and electron. It increases going to the right and down on the periodic table.