Warm Up 9-20-17 Explain why the atom is neutral with no charge. In the flame test how do we know which element absorb more energy? If a Bunsen burner doesn’t turn on, what could be the problem? Agenda Notes Unit 2-6 Turn in Lab Practice worksheet 2-6 Homework Sept 26 - Test Unit 2 Sept 26 - Notebook check Sept 26 - Online HW unit 2

Unit 2-6 Writing Electron Configuration

Writing Electron Configuration Use energy level and orbitals Read from left to right & top to bottom

Electron Configurations Example Do electron configuration for the first 13 elements Only record down the ending electron configuration for each orbital Try doing Ca, S, Ti, Fe

Electron Configuration Problems Try: Ca S Ti Fe 1s22s22p63s23p64s2 1s22s22p63s23p4 1s22s22p63s23p64s23d2 1s22s22p63s23p64s23d6

Exception Rules D orbitals are 1 less energy than the S orbital Cu and Cr electron config. are different

Orbital Filling Pauli Exclusion Principle No more than two electrons can be in the same orbital Aufbau Principle Electrons fill orbitals that have the lowest energy first Hund’s Rule Orbitals of the same quantum number are occupied by one electron before any pairing occurs

Orbital Filling Examples

E. Configuration (Short Hand)

E. Configuration Short Hand Notation Using the previous element in the last column as a base (bookmark) Sulfur = Ne as a base = Short hand = 1s2 2s2 2p6 3s2 3p4 1s2 2s2 2p6 [Ne] 3s2 3p4 Think of short hand notation as bookmarks. We’re going to start after the designated noble gas. Do more examples

Electron Configuration Exceptions: Cu = [Ar] 3d10 4s1 Cr = [Ar] 3d5 4s1

Check for understanding Write the short hand notation for: O, Mg, Zn

Assignments Summary: What is the difference between short hand and long hand electron configuration? Lab flame due before class is over 2-6 WS due next class

Homeroom 9-20-17 Digital citizen assessment Quote of the week