e config
DESCRIPTION
TRANSCRIPT
Quantum NumbersQuantum Numbers
1. Principal #1. Principal # 2. Ang. Mom. #2. Ang. Mom. # 3. Magnetic #3. Magnetic # 4. Spin #4. Spin #
energy levelenergy level
sublevel (s,p,d,f)sublevel (s,p,d,f)
orbitalorbital
electronelectron
Pauli Exclusion PrinciplePauli Exclusion Principle
– No two electrons in an atom can have the No two electrons in an atom can have the same 4 quantum numbers.same 4 quantum numbers.
– Each eEach e-- has a unique “address”: has a unique “address”:
General RulesGeneral Rules
Aufbau PrincipleAufbau Principle
– Electrons fill the Electrons fill the lowest energy lowest energy orbitals first.orbitals first.
– ““Lazy Student Lazy Student Rule”Rule”
General RulesGeneral Rules
The Diagonal RuleThe Diagonal Rule
2p3p4p5p6p7p
3d4d5d6d
4f5f
2s3s4s5s6s7s
1s
8s
WRONGRIGHT
General RulesGeneral Rules
Hund’s RuleHund’s Rule
– Within a sublevel, place one eWithin a sublevel, place one e-- per orbital per orbital before pairing them.before pairing them.
– ““Empty Bus Seat Rule”Empty Bus Seat Rule”
O
8e-
Orbital Diagram / Box & Arrow DiagramOrbital Diagram / Box & Arrow Diagram
Electron Configuration / SPDF NotationElectron Configuration / SPDF Notation
1s2 2s2 2p4
NotationNotation
1s 2s 2p
Shorthand ConfigurationShorthand Configuration
S 16e-
Valence Electrons
Core Electrons
S 16e- [Ne] 3s2 3p4
1s2 2s2 2p6 3s2 3p4
NotationNotation
Longhand ConfigurationLonghand Configuration
© 1998 by Harcourt Brace & Company
sp
d (n-1)
f (n-2)
1234567
67
Periodic PatternsPeriodic Patterns
Periodic PatternsPeriodic Patterns
Period #Period #– energy level (subtract for d & f)energy level (subtract for d & f)
A/B Group # A/B Group # – total # of valence etotal # of valence e--
Column within sublevel blockColumn within sublevel block– # of e# of e-- in sublevel in sublevel
s-block
1st Period
1s11st column of s-block
Periodic PatternsPeriodic Patterns
Example - Example - HydrogenHydrogen
1
2
3
4
5
6
7
Periodic PatternsPeriodic Patterns
Shorthand ConfigurationShorthand Configuration– Core eCore e--:: Go up one row and over to the Noble Go up one row and over to the Noble
Gas.Gas.– Valence eValence e--:: On the next row, fill in the # of e On the next row, fill in the # of e --
in each sublevel.in each sublevel.
[Ar] 4s2 3d10 4p2
Periodic PatternsPeriodic Patterns
Example - Example - GermaniumGermanium
Full energy levelFull energy level
1
2
3
4 5
6
7
Full sublevel (s, p, d, f)Full sublevel (s, p, d, f)
Half-full sublevelHalf-full sublevel
StabilityStability
Electron Configuration ExceptionsElectron Configuration Exceptions– CopperCopper
EXPECTEXPECT:: [Ar] 4s[Ar] 4s22 3d 3d99
ACTUALLYACTUALLY:: [Ar] 4s[Ar] 4s11 3d 3d1010
– Copper gains Copper gains stabilitystability with a full with a full d-sublevel.d-sublevel.
StabilityStability
Electron Configuration ExceptionsElectron Configuration Exceptions– ChromiumChromium
EXPECTEXPECT:: [Ar] 4s[Ar] 4s22 3d 3d44
ACTUALLYACTUALLY:: [Ar] 4s[Ar] 4s11 3d 3d55
– Chromium gains Chromium gains stabilitystability with a half-full d- with a half-full d-sublevel.sublevel.
StabilityStability
StabilityStability
Ion FormationIon Formation– Atoms gain or lose electrons to become more stable.Atoms gain or lose electrons to become more stable.– Isoelectronic with the Noble Gases.Isoelectronic with the Noble Gases.
OO2- 2- 10e10e- - [He] 2s[He] 2s22 2p 2p66
StabilityStability
Ion Electron ConfigurationIon Electron Configuration
– Write the eWrite the e-- config for the closest Noble Gas config for the closest Noble Gas
– EXEX: Oxygen ion : Oxygen ion O O2-2- Ne Ne