8.11 Electron Configurations 8.11 Electron Configurations Noble Gas Electron Configuration 1s 2s 2p Ne (Z=10) Valence electrons (orbitals with highest n) Inner shell e - Noble gases are unusually stable because they have completely filled orbitals Filled octet: 8e - They don’t want to gain or lose e - 8.11 Electron Configurations 8.11 Electron Configurations Noble Gas Electron Configuration 1s 2s 2p Ne (Z=10) To simplify the notation, chemists use the following notation to represent filled inner shells: [Noble Gas Chemical Symbol] [Ne] stands for 1s 2 2s 2 2p 6 8.12 e 8.12 e - Configurations & The Periodic Table Configurations & The Periodic Table 8.12 e - Configurations & Periodic Table 8.12 e 8.12 e - Configurations & The Periodic Table Configurations & The Periodic Table Important Point The filling order table provides a general guide…there are exceptions…we will discuss them 8.12 e 8.12 e - Configurations & The Periodic Table Configurations & The Periodic Table Groups run down…Periods run across Table Group 1 8.12 e 8.12 e - Configurations & The Periodic Table Configurations & The Periodic Table Groups run down…Periods run across Table Period 4 Group 1
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8.11 Electron Configurations8.11 Electron Configurations
Noble Gas Electron Configuration
1s 2s 2p
Ne (Z=10)
Valence electrons (orbitals with highest n)
Innershelle-
Noble gases are unusually stable becausethey have completely filled orbitals
Filled octet: 8e-
They don’t want to gain or lose e-
8.11 Electron Configurations8.11 Electron ConfigurationsNoble Gas Electron Configuration
1s 2s 2p
Ne (Z=10)
To simplify the notation, chemists use thefollowing notation to represent filled innershells:
[Noble Gas Chemical Symbol]
[Ne] stands for 1s22s22p6
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
8.12 e- Configurations & Periodic Table
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Important Point The filling order table
provides a general guide…there are
exceptions…we will discuss them
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Groups run down…Periods run across Table
Group 1
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Groups run down…Periods run across Table
Period 4
Group 1
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Elements in same group have same electron
configurations
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Group 1ns1
Group 17ns2np5
Group 18Noble gases
ns2np6
Excepthelium
1 valence e-
7 valence e-
“Octet”
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Group 1ns1
Group 17ns2np5
Group 18Noble gases
ns2np6
Excepthelium
1 valence e-
7 valence e-
“Octet”
Note: Quantum Number n corresponds to the Period Number
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Group 1ns1
Group 18ns2np6
Group 17ns2np5 *
* Except He
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Refer to “blocks” in the periodic table
according to which orbitals are being filled
s block, p block, d block, f block
s block & p block are Main Group Elements
d block are Transition Metals
f block are Lanthanides & Actinides (Rare- earth elements)
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
s blockMain Group Elements
p block
Filling nsorbitals
Filling nporbitals
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
s block
d blockTransition metals
p block
Filling (n-1)dorbitals
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
s block
d blockTransition metals
f block
p block
Filling (n-2)f orbitals
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
f orbitals start filling after lanthanum (Z=57) &
after actinium (Z=89)
La [Xe]5d16s2
Ac [Rn]6d17s2
Then the f orbitals start filling…# = no. of e-
[Xe]4f#5d16s2
[Rn]5f#6d17s2
Note La & Ac are d block f block
When f orbitals are filled…filling of the d resumes
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Note there are exceptions to the filling table
La [Xe]5d16s2
Ac [Rn]6d17s2
[Xe]4f#5d16s2
[Rn]5f#6d17s2
f block
One electrongoes into the6d orbitalbefore fillingthe 5f
One electrongoes into the5d orbitalbefore fillingthe 4f
You are not responsiblefor knowing this
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
f orbitals start filling after lanthanum (Z=57) &
after actinium (Z=89)
La [Xe]5d16s2
Ac [Rn]6d17s2
Many filling exceptions in the f block…you are not responsible for knowing theexceptions within the f block
Then the f orbitals start filling…# = no. of e-
[Xe]4f#5d16s2
[Rn]5f#6d17s2
f block
When f orbitals are filled…filling of the d resumes
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
s block
d blockTransition metals
f block
p block
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
s block ns#, n comes from period
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
s block ns#, n comes from period1s 1s
2s
4s3s
6s5s
7s
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
p blockp block ns2np# n comes from period
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
p blockp block ns2np#, n comes from period
2p
4p3p
6p5p
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
d blockTransition metals
d block ns2(n-1)d#, n comes from period
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
d blockTransition metals
d block ns2(n-1)d#, n comes from period
4d3d
6d5d
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
d blockTransition metals
d block ns2(n-1)d#, n comes from period
4d3d
6d5d
Note exceptions like Cr & Cu due to half-filled and filled d orbitalsYou are responsible for knowing these
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
f blockf block ns2(n-1)d1(n-2)f#, n comes from period
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
f block4f5f
Many exceptions thoughf block ns2(n-1)d1(n-2)f#, n comes from period
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
f blockf block ns2(n-1)d1(n-2)f# n comes from period
4f5f
Note you are notresponsible for knowing filling exceptions in the f block elements
Many exceptions though
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Write out the electronic configuration for Se?
How many valence electrons does Se have?Se: Z=34 …first we find it on the Table
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Identify the core noble gasconfiguration…[Ar]
Se is in Period 4
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Identify the core noble gasconfiguration…[Ar]
Se is in Period 4
4s2
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Identify the core noble gasconfiguration…[Ar]
Se is in Period 4
4s2 3d10
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Identify the core noble gasconfiguration…[Ar]
Se is in Period 4
4s2 3d10 4p4
1 2 3 4
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Identify the core noble gasconfiguration…[Ar]
Se is in Period 4
4s2 3d10 4p4
1 2 3 4
This totals 34 e- [Ar] gives 18+2+10+4=34
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Write out the electronic configuration for Se?
How many valence electrons does Se have?Se: Z=34
Se: [Ar]3d104s24p4
Se: [Ar]3d 4s 4p
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Write out the electronic configuration for Se?
How many valence electrons does Se have?Se: Z=34
Se: [Ar]3d104s24p4
Se: [Ar]3d 4s 4p
Check: Z=34… 18e-+ 10e-+ 2e-+ 4e- = 34e-
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Write out the electronic configuration for Se?
How many valence electrons does Se have?Se: Z=34
Se: [Ar]3d104s24p4
Se: [Ar]3d 4s 4p
Valence e- are outer shell (highest n) e-
Answer: 6 valence electrons in Se
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
You could determine this directlyfrom the periodic table as well
Group 16ns2np4
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
What element has the electron configuration
[Ar]3d64s2?
Consult the Periodic Table
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
The science behind “The Simpsons”“Homer goes to College”Come on, Mr. Simpson,
you'll never pass this course if you don't know the Periodic Table.
Ehh, I'll write it on my hand.HO! Including all known
Lanthanides and Actinides? HA HA!! Good Luck.
Note: you will be given the Periodic Table on exams and midterms!
8.12 e8.12 e-- Configurations & The Periodic TableConfigurations & The Periodic Table
Do problems on electron configurations
Attend a tutorial this week
Typical questions…how many valence
electrons…how many unpaired
electrons…what is the electron configuration
of “element name”
9.6 Magnetic Properties9.6 Magnetic Properties
9-6 Magnetic Properties
9.6 Magnetic Properties9.6 Magnetic Properties
Electron configurations affect behavior
of an atom in a magnetic field
9.6 Magnetic Properties9.6 Magnetic Properties
Spinning electron generates magnetic field
Spin Up
Spin Down
For “unpaired” single electron In an orbital…net mag. field or
9.6 Magnetic Properties9.6 Magnetic Properties
Spinning electron generates magnetic field
Spin Up
Spin Down
For “paired” electrons in an orbital…mag. fields cancel
9.6 Magnetic Properties9.6 Magnetic Properties
Diamagnetic atom or ion only has
paired electrons
Magnetic fields are cancelled out
Diamagnetic species are weakly
repelled by an external magnetic field
9.6 Magnetic Properties9.6 Magnetic Properties
Paramagnetic atom or ion has unpaired
electrons
Magnetic fields do not cancel out
Paramagnetic species are attracted
into an external magnetic field
9.6 Magnetic Properties9.6 Magnetic Properties
Determine electron configuration to see
if there are unpaired electrons
Mg [Ne] 3s
Paired electrons…diamagnetic
9.6 Magnetic Properties9.6 Magnetic Properties
Determine electron configuration to see
if there are unpaired electrons
Mg [Ne] 3s
Paired electrons…diamagnetic
Al [Ne] 3s 3p
unpaired electron
9.6 Magnetic Properties9.6 Magnetic Properties
Determine electron configuration to see
if there are unpaired electrons
Mg [Ne] 3s
Paired electrons…diamagnetic
Al [Ne] 3s 3p
unpaired electron…paramagnetic
9.6 Magnetic Properties9.6 Magnetic Properties
Would you expect Cl- to be attracted or
repelled by an external magnetic field?
Cl- [Ar] Paired electrons…Diamagnetic
Answer: Weakly repelled by externalmagnetic field
The OThe O++ ion is ____________.ion is ____________.
1. neutral2. diamagnetic3. It doesn’t exist.4. paramagnetic5. doubly charged
The OThe O++ ion is ____________.ion is ____________.
O: [He]2s22p4
O+: [He]2s22p3
Remember Hund’s rule of maximum
multiplicity.Therefore, 3 unpaired electrons
with parallel spins, i.e. O+ is paramagnetic.
What about O- and O2-?
Chapter 9 The Periodic TableChapter 9 The Periodic Table
The Periodic Table & Some Atomic
Properties
Primo Levi1919-1987
9.1 9.1 Classifying the ElementsClassifying the Elements
9-1 Classifying the Elements: The
Periodic Law & The Periodic Table
9.1 9.1 Classifying the ElementsClassifying the ElementsChemistry before the Periodic Table…messy
“…chemistry just now is enough to drive one mad. It gives me an impression of a primeval tropical forest, full of the most remarkable things, a monstrous and boundless thicket, with no way of escape, into which one may well dread to enter.”Friedrich
Wohler1800-1882
9.1 9.1 Classifying the ElementsClassifying the ElementsUntil Periodic Law proposed by Dimitri
Mendeleev & Lothar Meyer:
“Certain sets of properties recur periodicallywhen the elements are arranged in order of increasing atomic mass”
[Note: modern form uses increasing atomic number (Z)]
9.1 9.1 Classifying the ElementsClassifying the ElementsMendeleev and Meyer noticed patterns
Lothar MeyerGerman
Dimitri MendeleevRussian
9.1 9.1 Classifying the ElementsClassifying the Elements
Dimitri Mendeleev1834-1907
9.1 9.1 Classifying the ElementsClassifying the ElementsMendeleev left blanks in his periodic table
for undiscovered elements.
He predicted the properties the unknown
elements should have.
His predictions were confirmed when the
elements were found (e.g., germanium in 1886).
9.1 9.1 Classifying the ElementsClassifying the ElementsMendeleev predicted the properties for Ge
Germanium is in the same family as Si andthey share similar properties
9.1 9.1 Classifying the ElementsClassifying the ElementsMendeleev’s Table used atomic mass values
Blank(Germanium)
Mendeleev predictedproperties like Si
Germanium is in the same family as Si andthey share similar properties…powerful tool
9.1 9.1 Classifying the ElementsClassifying the ElementsModern Periodic Table: arrange according to
atomic number (Z)
9.1 9.1 Classifying the ElementsClassifying the ElementsGroups run down…Periods run across Table
Period 3
Group 14
Mohammed Abubakr, Hyderabad, IndiaMohammed Abubakr, Hyderabad, India
The Biochemical Periodic TableThe Biochemical Periodic Table
Yoshiteru Maeno at Kyoto University
bricks are the number of valence electrons for the neutral form of that element (main group
LEGO
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their Ions
9-2 Metals & Nonmetals & Their Ions
Platinum
Sulfur
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsMake predictions based on e- configurations
Metals Non Metals
Noblegases
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsMetals tend to give up electrons
Metals
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsNonmetals tend to gain electrons
Non Metals
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsNoble gases neither gain nor lose e-
Noblegases
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsRecall noble gas configuration ns2np6
Noblegases
*
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsNoble gases: complete octet ns2np6
Eight valence electrons: complete shell
Noble gas configuration is very stable
4s 4p[Ar]3d104s24p6
Metals lose electrons to achieve ns2np6 stabilityNonmetals gain electrons to achieve ns2np6
stability
Kr (Z=36) [Ar]3d10
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsMetals tend to lose electrons
39.098K19
[Ar]4s1
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsMetals tend to lose electrons
[Ar]4s1
K K+ + 1e-
[Ar]
Noble gasconfigurationfor the cation
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsMetals tend to lose electrons
137.33Ba56
[Xe]6s2
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsMetals tend to lose electrons
[Xe]6s2
Ba Ba2+ + 2e-
[Xe]
Noble gasconfigurationfor the cation
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsNonmetals tend to gain electrons
79.904Br35
[Ar]3d104s24p5
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsNonmetals tend to gain electrons
[Ar]3d104s24p5
Br -Br + 1e-
[Ar]3d104s24p6 = [Kr]
Noble gasconfigurationfor the anion
Kryptonite
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsNonmetals tend to gain electrons
32.06S16
[Ne]3s23p4
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsNonmetals tend to gain electrons
[Ne]3s23p4
S2-S + 2e-
[Ne]3s23p6 = [Ar]
Noble gasconfigurationfor the anion
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsTransition metal ions also lose electrons
47.88Ti22
[Ar]3d24s2
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsTransition metals also tend to lose electrons
Ti Ti2+ + 2e-
[Ar]3d24s2 [Ar]3d2
Note: Electronsare lost fromthe outermost orbital(not the last one filled)
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsTransition metal ions can achieve noble gas
configuration e.g., Ti4+
Ti Ti2+ + 2e-
[Ar]3d24s2 [Ar]3d2
Ti Ti4+ + 4e-
[Ar]3d24s2 [Ar]
Noble gas configuration
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsMost transition metal ions do not achieve
noble gas configuration e.g. Fe2+, Fe3+
Fe Fe2+ + 2e-
[Ar]3d64s2 [Ar]3d6
Fe Fe3+ + 3e-
[Ar]3d64s2 [Ar]3d5
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their Ions
Which would you expect to be more stable
Fe2+ or Fe3+?
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their Ions
Which would you expect to be more stable
Fe2+ or Fe3+?
Answer: Fe3+
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their Ions
Which would you expect to be more stable
Fe2+ or Fe3+?
Answer: Fe3+
Why? Extra stability associated with a
half-filled 3d shell.
Fe2O3
Fe3+
9.2 9.2 Metals Nonmetals & their IonsMetals Nonmetals & their IonsMost transition metal ions do not achieve
noble gas configuration
Cu Cu+ + 1e-
[Ar]3d104s1 [Ar]3d10 = [Ne]3s23p63d10
Pseudo noble gasconfiguration18e- in outer shell
9.3 9.3 The Sizes of Atoms & IonsThe Sizes of Atoms & Ions
9-3 The Sizes of Atoms & Ions
9.3 9.3 The Sizes of Atoms & IonsThe Sizes of Atoms & IonsThere are size trends for atoms and ions
9.3 9.3 The Sizes of Atoms & IonsThe Sizes of Atoms & IonsHow do we define atomic, ionic radius?
Electron probability cloud…border uncertain
We can determine internuclear distances
We define radii based on distance between
two nuclei
9.3 9.3 The Sizes of Atoms & IonsThe Sizes of Atoms & IonsCovalent Radius (for covalent bonded atoms)
r r
Internuclear distance is2 x atomic radius(same species)
O2 (oxygen molecule)
2r = 143 pm
So r = 71.5 pm
18931893Windsor,Windsor,OntarioOntario
9.3 9.3 The Sizes of Atoms & IonsThe Sizes of Atoms & IonsIonic Radius (for ionic bonded species)
Internuclear distance issum of the two radii
Na+Cl- (ionic compound)
rNa+ + rCl- = 280 pmInternuclear dist.
rNa+99pm
Na+ Cl-
If you know rNa+…you can calculate rCl-
rCl-181pm
9.3 9.3 The Sizes of Atoms & IonsThe Sizes of Atoms & IonsMetallic Radius (for metal atoms in crystal)
Crystalline Solid MetalAg Ag
Internuclear distance is2 x metallic radius
(same species)
2r = 288 pmSo r = 144 pm
r r
2r
9.3 9.3 The Sizes of Atoms & IonsThe Sizes of Atoms & IonsWhat are the radii of Li+ and of I-?