Electron Orbitals and Orbital Filling Diagrams

Remember the Bohr Atom We can simplify this diagram…

Representing Energy Levels Energy levels going away from nucleus. Nucleus down here

Energy Levels Within Atom Within each energy level, there are sub-levels called orbitals. Each energy level has a different number of sub-levels. n=4 d n=3 p s E p Sublevels n=2 s n=1 s Principle Energy Levels (n)

Orbitals Orbitals given designations: s p d f

Orbitals Orbitals: specific defined space that there is a high probability of finding the electron(s) s p d

Brain Break: Your Choice for 30 seconds Arm Circles Squats Lunges Wall Sit Punches Skier Jog in Place Inclined Push-Ups Other

Another way we represent electrons in an atom is by the electron configuration. There are a couple of methods we can use to write out an electron configuration. Orbital Filling diagrams From the periodic table Orbital boxes Noble Gas Notation

Orbital Filling Diagram Determine the number of electrons the atom has. Start at the lowest energy level and fill up. (Aufbau principle) Only two electrons per orbital. (Pauli exclusion principle.) For the p, d, and f orbitals, fill each degenerate level with one electron, then go back and add more. (Hund’s rule). Once the diagram is filled, condense the diagrams to write out the electron configuration.

Example Complete this diagram for the element, Arsenic (As)

Example Complete this diagram for the element, Potassium (K)

On Your Paper… Mg Al H C Cl Ne

Electron Configurations • shorthand method of representing electron filling • the “address” of the e-’s in an atom • determined by filling order (Aufbau, Pauli exclusion, Hund’s rule)

Electron Configurations # of electrons Example: Nitrogen 1s22s22p3 Orbital type (or sublevel) Energy level

Electron Configurations Note: • energy levels included with every orbital! • use lower case letters for orbital types (3p NOT 3P) • # of e- in orbital --> superscript