Electron Configurations Electron configurations are...
Electron Configuration Vocab Principle Energy Level correlates to the period (1-7), periods go from left to right across the periodic table Sublevel are located in the principle energy level. There are 4 that we will talk about s, p, d and f. Orbital located in the sublevel. Where electrons are most likely to be found 1 ORBITAL HOLDS 2 ELECTRONS
Writing Electron Configurations Principle Energy Level[sublevel]number of electrons OR a[b] c Get your periodic table! Start from left to right!
Orbital Diagrams Tool for creating electron configurations 2 dimensional representation of where electrons are in an atom
Aufbau Principle electrons are added to the lowest available energy level. Hydrogen as an example:
Pauli Exclusion Principle each orbital can hold two electrons those electrons must have opposite spins spin is represented by the arrow facing up or down.
Hunds Rule Orbitals of equal energy are occupied by one electron before 2 electrons occupy 1 orbital. The second electron is added after all orbitals have one electron
Noble Gas Configuration – Short cut Locate the element on the PT Trace backward to the nearest noble gas Put that noble gas in  (brackets) Fill in remaining electrons
P orbitals in more detail p sublevel 3 orbitals x, y & z Work like a coordinate plane Atoms are 3-D
Valence Electrons Electrons in the HIGHEST energy level (n) Electrons that interact during chem rxns Always in the s & p sublevels
Finding Valence Electrons Locate the highest energy level Count the electrons present Orbital diagrams SUPER helpful Example: Sulfur How many valence es?
Stability – Hunds Rule Exceptions to e configs In the d-block (yo) Almost ½ filled d-block Almost full d-block It is more stable for atoms to have 2 half filled sublevels Compared to 1 full and 1 partially filled Example: Chromium