Compounds & Chemical Bonds
View: How atoms bond George Zaidan and Charles Morton!
https://www.youtube.com/watch?v=NgD9yHSJ29I!
Electrons, Configurations, & Bonds Noble Gases and The Rule of Eight
! When a nonmetal and a metal
combine, they form an ionic bond:
Valence electrons of the metal are lost
and the nonmetal gains these electrons
to achieve a Noble gas electron
configuration.!
ð  When two nonmetals combine, they
form a covalent bond: They share
electrons to achieve a Noble gas
electron configuration.!
ð 
Ionic vs. Covalent Bonding
Compounds & Chemical Bonds
!Atoms in a compound (molecule) are in
ratios of whole numbers with specific 3
-dimensional arrangements due to
attractive inter-atomic forces (Bonds).
These provide favorable energy states
& spatial positions (lower energy &
farther apart are better), which result in
molecules having new chemical,
physical, and biological properties.!
Compounds & Chemical Bonds
View: Types of Chemical Bonds!
Hank Green / Crash Course!
https://www.youtube.com/watch?v=QXT4OVM4vXI!
Electronegativity
Periodic Table
Properties & Organization
http://chemconnections.org/general/movies/html-swf/periodictrends.htm!
Periodic Table
Properties & Organization
QUESTION
Periodic Table
Properties & Organization
http://chemconnections.org/general/movies/html-swf/periodictrends.htm!
QUESTION
Number of Valence Electrons for Elements in
the “A” lettered Vertical Columns Equal the
Column Number!
Ionic Bonds
 
Result from electrostatic attractions of closely
packed, oppositely charged ions.
 
Form when an atom, which can easily lose electrons
reacts with one which has a high electronegativity,
that is, it can easily gain electrons. The vertical A
column number (# of valence electrons) in the
Periodic Table indicates the ion that forms and the
number of electrons gained or lost.!
Eg. Na (-1e-) and Cl (7e-; +1 e-); Mg (-2e-) and Br
(7e-; +1 e-) ; K (-1e-) and O (6e-; +2 e-)!
 
Ionic Compounds
Neutrally Charged!
Eg. Salt: NaCl → 1 Na+ and 1 Cl - !
ð  What is the proportion of ions for a
compound formed from Mg ion and
chlorine?!
ð  Mg2+ and Cl-
ð  1 Mg2+ combines with 2 Cl-
ð 
ð 
Electron Configurations!
QUESTION
!Predict the formula for the binary ionic compound formed by aluminum and oxygen.!
A) Al2O3
!B) Al3O2
!C) Al2O
!D) AlO2
Ionic vs. Molecular (Covalent) Compounds
Salt (ionic) vs. Water (covalent)!
http://chemconnections.org/general/movies/html-swf/comp_molec_ionic_co.htm!
Covalent Chemical Bonds
Molecular Compounds
View: Hank Green!
Crash Course!
https://www.youtube.com/watch?v=bD-SH1ASbjw!
Lewis Structures (Named after Prof. G. N. Lewis UC Berkeley)
  Show
how valence electrons are arranged
among atoms and in a molecule;
particularly useful for covalent molecules.
  Reflects
central tenet that stability of a
compound relates to noble gas electron
configuration.
  Shows
bonds and relates to 3-dimensional
shapes in molecular structures.!
G.N. Lewis
Photo Bancroft Library, University of California/LBNL Image Library
Footnote:
G.N. Lewis, despite his insight and contributions
to chemistry, was never awarded the Nobel prize.
Lewis Electron-Dot Drawings
Periods 2 & 3
http://chemconnections.org/general/movies/LewisDotStructures.swf!
Shapes of Molecules
View: What is the shape of a molecule?
George Zaidan and Charles Morton!
Eg. Ammonia:!
https://www.youtube.com/watch?v=Jq_Ca-HKh1g!
Lewis Structures / VSEPR Molecular Models for C, H, N, O
 
Fundamental repeating shapes found in every
biological molecule!
Lewis Structures / VSEPR Molecular Models for C, H, N, O
 
Fundamental repeating shapes found in every
biological molecule!
C =black!
H = gray!
N = blue!
O = oxygen!
http://chemconnections.org/general/movies/html-swf
/vsepr_four_electron.htm!
C =black!
H = gray!
N = blue!
O = oxygen!
pink =
generic
atom!
Polyatomic Ions
Discrete units of covalently bonded atoms that behave as ions
pink = generic
atom!
QUESTION
Which formula containing polyatomic ions is correct?!
!A) MgNO3
!B) NH4CO3
!C) Na(PO4)3 !D) Al2(SO4)3 !
http://chemconnections.org/general/chem120/polyatomics.html
Chemical Formulas &
Molecular Representations
How many hydrogens, oxygens, and carbons are there in:!
ethanol?!
ethylene glycol?!
aspirin?!
Red spheres are oxygen, the white/gray are hydrogen, and black carbon.!
Structural Representations of Quinine!
Proteins & Small Molecules
Structure-Odor Relationships
Karen J. Rossiter, Chem. Rev., 1996, 96, 3201-3240
http://dvcchem.org/COT/chemical-communication/ChemComm.html!
Shapes & Interactions: Mirror Images & Smell
http://ep.llnl.gov/msds/orgchem/Chem226/Smell-Stereochem.html