Periodic Table

1
Periodic Table

• Metals
• Nonmetals
• Main Group
• Noble gases
• Transition metals
• Lanthanides Actinides

2
Metals
3
Nonmetals
4
Main Group Elements
5
Noble Gases
6
Transition Metals
7
Lanthanides and Actinides
8
Ionic Charges of Main Group
1
III
V
IV
II
VI
VII
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Main Group Ions

• Group I and II cations that correspond to group
  number
• Na, Mg2, Sr2
• Group III Al (Ga) Group number Al3
• Group IV no monatomic ions
• Group V, VI, VII anions that are 8 group
  number N3-, S2-, Br

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1 Predict the charges on the ions formed from
the following Main Group atoms

• Mg
• Cl
• F
• N
• P
• K
• Ba

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1 Predict the charges on the ions formed from
the following Main Group atoms

• Mg
• Cl
• F
• O
• P
• K
• Ba

• Mg2
• Cl
• F
• O2
• P3
• K
• Ba2

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Periodic Table

• Law versus Theory
• Scientific Law
• Empirical observation
• No known exceptions
• Often a relationship between properties

13
Periodic Table

• Scientific Theory
• Principles that explain observations associated
  w/ laws
• Testable and tested
• Periodic Table
• Mendeleev Meyer
• Empirical observations
• Atomic Theory came much later

14
Periodic Properties Atomic Size

• Atoms are not billiard balls.
• Radial Electron Density (Atomic Radius)
• Effective Nuclear Charge, Zeff
• Z number of protons
• Zeff lt Z
• Shielding or screening by inner shell electrons

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Atomic Radius
Nuclear charge is screened by inner shell
electrons Zeff lt Z
Z
n1
n2
n3
16
Atomic Radius

• Same shell electrons do not screen as well as
  inner shell electrons.
• Zeff ? as you fill a shell (move across row of
  periodic table)
• Na Mg Al Si P S Cl Ar

Increasing Z (1)
Screening lt 1 Zeff ?
Zeff Z S
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Atomic Radius

• Atomic radius ? as you move across row
• Atomic radius ? as you move down column

Size decreases
Size increases
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Problem 2

• Arrange each of the following groups of atoms in
  order of increasing size
• Cl, Mg, Si
• Ge, Pb, C

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Problem 2

• Cl lt Si lt Mg
• C lt Ge lt Pb

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Ionic Size in an Isoelectronic Series

• Isoelectronic Series N3 O2 F Ne Na
  Mg2 Al3

Size decreases
Same electron configuration Increasing Z
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Periodic Properties Ionization Energy

• Ionization Energy
• M energy ? M e

Ionization energy, In
M energy ? M2 e I2
As Zeff ?, In ?
Photoelectric effect I1 Eh?o
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Ionization Energy
Ionization Energy Increases
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Problem 3

• Arrange the following groups of atoms in order of
  increasing ionization energy.
• Cr, N, Rb, F
• Ar, In, P, Ba,

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Problem 3

• Rb lt Cr lt N lt F
• Ba lt In lt P lt Ar

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Ionization Energies
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Other Periodic Trends

• Physical properties
• Ion formation
• Reactivity

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Other Periodic Trends

• Alkali metals
• Form 1 ions
• Very reactive with O2, water
• Gray, soft metals
• Always found in compound form

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Other Periodic Trends

• Alkaline earths
• Form 2 ions
• Less reactive

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Other Periodic Trends

• Halogens
• Form 1 ions, very negative
• electron affinities
• Very reactive with metals to form MnXy

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Other Periodic Trends

• Noble Gases
• Monatomic
• Very unreactive (Xe, Kr)
• Large I1