CHM 143 Lecture Notes - Lecture 20: Principal Quantum Number, Valence Electron, Pauli Exclusion Principle

• School: Oakland University
• Department: Chemistry
• Course: CHM 143
• Professor: Tillinger

Document Summary

*the electron arrangement determines much of the properties (chemical) for an atom. Periodic law: elements are arranged in the periodic table such that they are placed in order by increasing atomic number and in columns ( groups ) based on similar chemical properties. Electron configuration: placing electron in subshells based on the amount of energy they possess. *need to know how many electrons need to be placed = atomic number. Fill subshells from lowest energy to highest energy until all electrons are used up. *start with lowest energy = always 1s for ground state. Transition metals: some do not follow the aufbau principle. *greater stability in a half filled s and half or full d subshell. Electron configurations for ions: anion or cation, how many electrons is based on the charge, atoms gain or lose electrons to have the electron configuration of nearest noble gas, cations: lose electrons from outermost subshell. (increase shell number)