Fred J' Grieman

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Fred J. Grieman
Atomic properties to consider when forming
molecules Measurement of atomic orbital
energies Periodic Properties Prediction based
on Coulombic Interactions Ionization
energy Electron affinity Atom size
Electronegativity
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Measurement of orbital energies First Remember
photoelectric effect light absorbed by metal
ejects electrons
Ek
E
h?
Work function
h?o
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Measurement of orbital energies
Measurement of orbital energies
Measurement of orbital energies
ionization region
different Ek (e-)
h?
2p
2s
E
?Esubshell
?Eshell
1s
1s 2s

2p
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Fig. 17-5
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• Periodic properties
• Basis
• V
• V
• V
• V
• Actual Properties

charges
distance between charges
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First Ionization Energy
Predictions across period
down group change period
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Electron Affinity Attraction of e- to neutral
atom
Predictions across period
Exceptions
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Atom and Ion Size
Atomic radius Metals Nonmetals Ions
Predictions Group Period
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Electronegativity
Measure of shared electron attraction to atom
in molecular bond
Mulliken-Jaffe Scale Based on atomic
properties
Pauling Scale
Based on molecular properties BE(AB)
(BE bond energy)
BE(AA).BE(BB)1/2 96.48(EN(A) EN(B)2

part of bond Assumptions
Set EN(F) 4.0 (Actually, 3.98)
O (3.4) F (3.9) S (2.7) Cl (3.1)
Br (3.0)
O (3.5) F (4.0) S (2.5) Cl (3.0) Br (2.8)
Pauling Scale preferred
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Electronegativity Predictions? Across period Down
group