CHEM 1A Lecture Notes - Pauli Exclusion Principle, Electron Configuration

• School: UC-Irvine
• Department: Chemistry
• Course: CHEM 1A
• Professor: Amanda Brindley

Document Summary

Pauli exclusion principle states that no two electrons can have all four quantum numbers be the same. Fill in electrons in order of energy levels. Hund"s rule- fill across degenerate energy levels before filling orbital. Half filled and full filled orbitals are more stable. To get d orbitals to this stability promote electrons from s orbitals. When valence d orbitals have electrons and you need to make an positive ion, remove from valence s orbitals first. Fs also have a bunch of exceptions, don"t worry about these. If i ask for an electron configuration from the f block, just follow the rules. Simply add or subtract electrons based on the charge of the ion. Example: co to co2+ take away two electrons. 1s22s22p63s23p63d7 or [ar] 3d7 add or subtract electrons based on the charge of the ion. Electron configuration of neutral chromium requires promotion of electron. Electron configuration of neutral chromium requires promotion of electron to give stable half shell.