Welcome to Day 31! September 3x10 1, 2009 Objectives changed last minute SWBAT Draw orbital diagrams SWBAT show electrons using electron configuration Catalyst (1)Pick up a chemistry book from the back or under your chair and turn to pg Look at figure 5-18, that is the quantum mechanical model for a Neon atom. (2)What data did Rutherford discover and how did this data change the model of the atom? (3)Draw a Bohr model for the following elements: (a) Beryllium

Agenda  Catalyst Review 15min  Orbital Diagrams 15min  Practice 10min  Electron Configuration Notation 10min  Practice! 20min  Exit ticket 10min

ANNOUNCEMENTS  Quiz This Friday  Unit 2 Test next Friday

Orbital Diagrams and Electron Configuration Notation Ch. 5, sections 2 and 3

Orbital Diagrams & Electron Configuration We need ways to keep track of where electrons are located in an atom

Orbital Diagrams & Electron Configuration Bohr Models Orbital Diagrams Electron configuration

BOHR MODEL  Electrons orbit nucleus in defined, circular orbits.

QUANTUM MECHANICAL MODEL Electrons reside in:  LEVEL (like the Bohr model) Ex. 1, 2, 3, 4,...  Within a level, they reside in a SUBLEVEL Ex. s, p, d, f  Within a sublevel, they reside in an ORBITAL Ex. Fig 5-18

s and p Orbitals

III. Quantum Mechanical Model: Atomic Orbitals E. Shapes of orbitals d orbitals

Electron Configuration & Bohr Models There are 4 orbitals: some pirates die fiercely

Four Sub-Energy Levels Sub Level (Type of orbital) Shape# of Orbitals Max # of electrons sSphere12 pDumbbell (peanut) 36 d4-Lobed (double- peanut) 510 f6-8 Lobed (flower) 714

How do we arrange electrons in an atom?  electrons in an atom want to assume the arrangement with the lowest energy; the lower the energy, the more stable the arrangement.

What rules do electrons follow? (1)Aufbau Principle: Electrons fill the lowest energy sublevels first.

2) Pauli Exclusion Principle  Electrons within an orbital must have opposite spins. An arrow pointing up ( ↑ ) represents an electron spinning one direction An arrow pointing down ( ↓ ) represents an electron spinning in the opposite direction

3) Hund’s Rule Every orbital in a sublevel is singly occupied with one electron before any one orbital is doubly occupied. 2p orbital

Orbital Box Diagram

Example: Zinc START Atomic # = # of electrons =

Example: Argon START Atomic # = # of electrons =

Example: Calcium START Atomic # = # of electrons =

Electron Configuration  Electron configuration is a way of writing out how electrons are arranged.

Electron Configuration Symbols 5f 35f 3 Energy Level Sub-Energy Level # of e - in sub-energy level

Electron configuration:  Go back to Zn, Ar, and Ca

Practice with Whiteboards Orbital diagram and electron configuration for:  Phosphorus.

Periodic Table Trick

Individual Practice Please draw the orbital box diagram and write the electron configuration for the following elements: (1)Boron (2)Lithium (3)Silicon (4)Sodium (5)Titanium (6)Iron (7)Selenium (8)Galium

Homework  Draw the orbital box diagram and electron configuration for the following elements: (1)Beryllium (2)Aluminum (3)Argon (4)Vanadium  Memorize the names and symbols of the 1 st 20 elements on the periodic table

Exit Slip #1 (1) Write the electron configuration for Sulfur.