CHE 101 Lecture Notes - Lecture 9: Electron Configuration, Effective Nuclear Charge, Xenon Hexafluoride

• School: University at Buffalo
• Department: Chemistry
• Course: CHE 101
• Professor: Atwood Jim

Document Summary

Periodic properties of the elements: shielding and effective nuclear charge, atomic size, ionization energy, electron affinity, descriptive chemistry of selected elements. Cations- the electrons with largest n come off (largest distance for nucleus) first. Na+ [ne] 1s^2 2s^2 2p^6 or [ne: cl. Cl - [ne] 3s^2 3p^6: mn 2+ The periodic table was derived because some elements have similar properties. In chapter 6 we found that electron configurations play a role: shielding and effective nuclear charge. Shielding and effective nuclear charge are the keys to understanding atomic size and ionization potential. An electron is attracted to the nucleus with the amount of attraction directly proportional to the nuclear charge experienced by that electron. The 1s electron shield the 2s electron from the nuclear charge such that the 2s electron is attracted by a nuclear charge of about 1 (actually 1. 3); this is the effective nuclear charge. The effective nuclear charge on the 2s electrons of be is 1. 9.