13Electron Configurations Electron configurations are...
14Electron Configuration Vocab Principle Energy Levelcorrelates to the period (1-7), periods go from left to right across the periodic tableSublevelare located in the principle energy level. There are 4 that we will talk about s, p, d and f.Orbitallocated in the sublevel. Where electrons are most likely to be found1 ORBITAL HOLDS 2 ELECTRONS
15Writing Electron Configurations Principle Energy Level[sublevel]number of electrons ORa[b]cGet your periodic table!Start from left to right!
16Orbital Diagrams Tool for creating electron configurations 2 dimensional representation of where electrons are in an atom
17Aufbau Principleelectrons are added to the lowest available energy level.Hydrogen as an example:
18Pauli Exclusion Principle each orbital can hold two electronsthose electrons must have opposite spinsspin is represented by the arrow facing up or down.
19Hund’s RuleOrbitals 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
22Noble Gas Configuration – Short cut Locate the element on the PTTrace backward to the nearest noble gasPut that noble gas in  (brackets)Fill in remaining electrons
23P orbitals in more detail p sublevel3 orbitalsx, y & zWork like a coordinate planeAtoms are 3-D
24Valence Electrons Electrons in the HIGHEST energy level (n) Electrons that interact during chem rxnsAlways in the s & p sublevels
25Finding Valence Electrons Locate the highest energy levelCount the electrons presentOrbital diagrams SUPER helpfulExample: SulfurHow many valence e’s?
26Stability – Hund’s Rule Exceptions to e configsIn the d-block (yo)Almost ½ filled d-blockAlmost full d-blockIt is more stable for atoms to have 2 half filled sublevelsCompared to 1 full and 1 partially filledExample: Chromium