Welcome to Day 31! September 3x101, 2009

Objectives changed last minuteSWBAT Draw orbital diagramsSWBAT show electrons using electron configuration

Catalyst

(1) Pick up a chemistry book from the back or under your chair and turn to pg. 137. 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 OrbitalsE. Shapes of orbitals

d orbitals

Electron Configuration & Bohr Models

There are 4 orbitals:some

piratesdie

fiercely

Four Sub-Energy Levels

Sub Level (Type of orbital)

Shape # of Orbitals

Max # of electrons

s Sphere 1 2

p Dumbbell (peanut)

3 6

d 4-Lobed (double-peanut)

5 10

f 6-8 Lobed (flower)

7 14

How do we arrange electrons in How do we arrange electrons in an atom?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)(1) Aufbau Principle:Aufbau Principle:Electrons fill the lowest energy sublevels

first.

2) Pauli Exclusion Principle2) 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 Rule3) 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 3

Energy LevelSub-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 PracticePlease 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 1st 20 elements on the periodic table

Exit Slip #1

(1) Write the electron configuration for Sulfur.