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
