Electron Configuration Atomic Structure and

Orbital (“electron cloud”) – Region in space where there is 90% probability of finding an e - Each orbital letter has a different shape.

“s” orbital spherical shaped

“p” orbital Dumbbell shaped Arranged x, y, z axes

“d” orbital clover shaped

“f” orbital f Orbitals combine to form a spherical shape. 2s 2p z 2p y 2p x

Rules for e - configurations Aufbau principle 1. Aufbau principle: e - enter orbitals of lowest energy level ( Hogs are lazy, they don’t want to walk up stairs!) Pauli exclusion principle 2. Pauli exclusion principle: an atomic orbital may describe at most 2 e -, e - in the same orbital will spin in opposite directions ( They stink, so you can’t put more than two hogs in each room. & If hogs are in the same room they will face in opposite directions.) Hund’s rule 3. Hund’s rule: when e - occupy orbitals of = energy, 1 enters each orbital until all the orbitals contain 1 e - w/parallel spins ( Hogs want to room by themselves, but they would rather room with another hog than walk up more stairs.)

Now you will relate the “Hog Hilton” to electron orbitals. Electron orbitals are modeled by the picture on the left and are grouped into principal energy levels. 1. Compare their similarities and differences. 2. To go between floors on the Hog Hilton did the hogs need to use energy? Would electrons need to use the energy to go between orbitals. 3d ___ ___ ___ ___ ___ n=3 (4s ____) n=4 3p ___ ___ ___ n=3 3s ___ n=3 2p ___ ___ ___ n=2 2s ___ n=2 1s ___ n=1 6th floor ___ 5th floor ___ ___ ___ 4th floor ___ 3rd floor ___ ___ ___ 2nd floor ___ 1st floor ___

A. The principal quantum numbers, (n) Electrons are in designated energy levels. Organization of e- in the Quantum Mechanical model The ground state- the lowest energy state of the atom

B. Within the energy level are sublevels, designated by letters. Principal energy level (n) Number of sublevels Type of Orbital 1 st energy level1 sublevel“s” (1 orbital) 2 nd 2 sublevels“s” (1) & “p” (3 orbitals) 3 rd 3 sublevels“s”(1), “p” (3) & “d” (5 orbitals) 4 th 4 sublevels“s”(1), “p”(3), “d”(5), and “f” (7)

1s 2s 2p 3p 3s 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p7f 7s 7p 6s 6p 6d 6f 6g 5s 5p 5d 5f 5g 4s 4p 4d 4f 3s 3p 3d 2s 2p 1s

Filling in orbitals then writing the electron configuration 4p _ ↑↓ _ _ ↑ _ _ ↑ _ 3d _ ↑↓ _ _ ↑↓ _ _ ↑↓ _ _ ↑↓ _ _ ↑↓ _ 4s _ ↑↓ _ 3p _ ↑↓ _ _ ↑↓ _ _ ↑↓ _ 3s _ ↑↓ _ 2p _ ↑↓ _ _ ↑↓ _ _ ↑↓ _ 2s _ ↑↓ _ 1s _ ↑↓ _ What element is this? Count the electrons to find out… 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 4 Using the Noble Gases to write Shorthand Write the noble gas that is in the previous row. Use the symbol of the noble gas, put it in brackets, then write the rest of the configuration. When we write the e- config using Noble Gas notation… It would be written [Ar] 4s 2 3d 10 4p 4