Shows the electronic structure of atoms including energy level diagrams, s, p, d and f orbitals and their relationship to the Periodic Table of Elements **More good stuff available at: www.wsautter.com and http://www.youtube.com/results?search_query=wnsautter&aq=f

1. Copyright Sautter 2015

2. ELECTRONIC CONFIGURATION OF ATOMS
USING ENERGY LEVEL DIAGRAMS
FOR
ATOMS
&
IONS

3. WHAT IS AN ELECTRONIC CONFIGURATION?
• ELECTRONIC CONFIGURATIONS SHOW THE
ENERGY STATES (ARRANGEMENTS) OF
ELECTRONS WITHIN DIFFERENT ATOMS
• FOR EXAMPLE WE CAN DETERMINE FROM THE
PERIODIC TABLE THAT HYDROGEN ATOMS
(ATOMIC NUMBER =1) HAVE BUT ONE ELECTRON
WHILE OXYGEN (ATOMIC NUMBER = 8) HAS
EIGHT ELECTRONS, BUT HOW ARE THEY
ARRANGED WITH EACH ATOM?
3

4. DETERMINING ELECTRON CONFIGURATIONS
• IN ORDER WRITE A CORRECT CONFIGURATION
FOR AN ATOM WE MUST:
• (1) FIND THE NUMBER OF ELECTRONS THE
ATOM CONTAINS
• (2) USE THE ENERGY LEVEL DIAGRAM TO
DETERMINE THE ORBITIAL LOCATIONS OF THE
ELECTRONS
• (3) PLACE THE ELECTRONS IN THE PROPER
ORBITALS USING TWO FUNDAMENTAL RULES
(THE PAULI EXCLUSION PRINCIPLE AND HUND’S
RULE)
4

5. ORDER
OF
ENERGY
LEVEL
FILLING
5

6. 6

7. DETERMINING ELECTRON CONFIGURATIONS
(CONT’D)
• THE PAULI EXCLUSION PRINCIPLE STATES
THAT A MAXIMUM OF TWO ELECTRONS
(EACH WITH OPPOSITE SPINS) MAY OCCUPY
AN ORBITAL
• HUND’S RULE STATES THAT ORBITALS OF
EQUAL ENERGY MUST BE FILLED WITH
ELECTRONS ONE AT A TIME UNTIL ALL OF
THE ORBITALS ARE HALF FILLED, THEN
FILLING MAY BE COMPLETED RESULTING IN
EACH ORBITAL CONTAINING TWO
ELECTRONS MAXIMUM
7

8. DETERMINING ELECTRONCONFIGURATIONS
(CONT’D)
• ELECTRONS ARE ADDED TO THE ENERGY
LEVEL DIAGRAM ACCORDING TO THE
RULES PREVIOUSLY OUTLINED USING AN
ARROW TO REPRESENT EACH ELECTRON.
• EACH ORBITAL MAY CONTAIN A
MAXIMUM OF TWO ARROWS, ONE
POINTED UPWARD AND ONE POINTED
DOWNWARD TO SHOW THE OPPOSITE
SPINS OF THE PAIRED ELECTRONS.
• NOW LET’S SHOW THE ELECTRON
CONFIGURATION FOR THE HYDROGEN
ATOM.
8

9. Electronic
Configuration
For
Hydrogen
(1 electron)
Energy Level
Number
Orbital
Type
Number of
Electrons in
the Orbital
9

10. DESCRIBING ELECTRON CONFIGURATIONS
OF ATOMS
• ELECTRON CONFIGURATIONS MAY BE REPRESENTED
IN WRITTEN FORM OR DIAGRAMATIC FORM.
• IN WRITTEN FORM, THE ENERGY LEVEL NUMBER IS
WRITTEN FIRST FOLLOWED BY THE ORBITAL
DESIGNATION AND FINALLY THE NUMBER OF
ELECTRONS PRESENT IN THE ORBITAL IS SHOWN AS A
SUPERSCRIPT.
• FOR EXAMPLE, SODUIUM Na WITH 11 ELECTRONS
WOULD BE WRITTEN AS 1s2 2s2 2p6 3s1
• IN THE 1S2 TERM THE NUMBER 1 STANDS FOR THE
ENERGY LEVEL, S FOR THE ORBITAL TYPE AND THE
SUPERSCRIPT 2 MEANS TWO ELECTRONS ARE PRESENT
10

11. 11
Click Here