1. Atomic theory of matter, 1807 – John Dalton (paraphrased postulates)
Elements are composed of atoms, which are very small
Atoms of a given element are identical and different from atoms of another element*
Atoms cannot be changed, destroyed, or created in a chemical reaction*
Compounds are formed from atoms and the relative quantity and identity of atoms are always the same for a given pure compound

2. J.J. Thompson – cathode ray tubes – charge-to-mass ratio of electrons
Robert Millikan – oil-drop experiment – charge on electrons (therefore mass)
Marie Curie – radioactivity – identified sub-atomic particles
Ernest Rutherford – gold leaf experiment – revealed the nuclear atom

3. Cathode Rays and Electrons

4. Cathode Rays and Electrons

5. Radioactivity

7. AN EXAMPLE: fill in the following chart
Symbol 52Cr
Protons
Neutrons
Electrons
Mass #

9. Chemical Nomenclature
Common names (water, ammonia, etc.)
Ionic compounds
Cations
Group 1 and 2 metals (first 2 columns): same name as element
Transition metals
Add Roman numeral to denote charge: e.g. Fe3+  Iron (III)
Or, use Latin names: e.g. Fe3+  ferric ion, Fe2+  ferrous ion
Molecular cations tend to end in “ium”: e.g. NH4+  ammonium, H3O+  hydronium

10. Chemical Nomenclature
Common names
Ionic compounds
Cations
Anions
Monatomic anions: replace suffix with “ide”
Cl-  chloride
N3-  nitride
Polyatomic anions containing oxygen (oxyanions)
Most “common”  ends in “ate”
One less oxygen than “ate” version  ends in “ite”

11. Chemical Nomenclature
Common names
Ionic compounds
Cations
Anions
Monatomic anions: replace suffix with “ide”
Polyatomic anions containing oxygen (oxyanions)
Most “common”  ends in “ate”
One fewer oxygen than “ate” version  ends in “ite”
One more oxygen than “ate” version  starts with “per” / ends in “ate”
One fewer oxygen than “ite” version  starts with “hypo” / end in “ite”
ClO-  hypochlorite
ClO2-  chlorite
ClO3-  chlorate
ClO4-  perchlorate

12. Chemical Nomenclature
Common names
Ionic compounds
Cations
Anions
Monatomic anions: replace suffix with “ide”
Polyatomic anions containing oxygen (oxyanions)
Oxyanions containing hydrogen
One hydrogen: add “hydrogen” to start of name (add +1 to charge)
Two hydrogens: add “dihydrogen” to start of name (add +2 to charge)
PO  phosphate
HPO42-  hydrogen phosphate
H2PO4-  dihydrogen phosphate

13. Chemical Nomenclature
Common names
Ionic compounds
Cations
Anions
Compounds (omit subscripts in name)
LiF  ?
aluminum sulfite  ?
FeHPO4  ?

14. Chemical Nomenclature
Common names
Ionic compounds
Cations
Anions
Compounds
Hydrates (some ionic compounds include “waters of hydration”)
FeCl3  iron (III) chloride
FeCl3 • 6H2O  iron (III) chloride hexahydrate

15. Chemical Nomenclature
Common names
Ionic compounds
Acids (anions with hydrogen cations)
From anions ending in “ide”  prefix “hydro”, change “ide” to “ic acid”
From oxyanions
For oxyanions ending in “ate”  change “ate” to “ic acid”
For oxyanions ending in “ite”  change “ite” to “ous acid”
HI  hydroiodic acid
HNO3  nitric acid (H2SO4  sulfuric acid)
HClO  hypochlorous acid

16. Chemical Nomenclature
Common names
Ionic compounds
Acids
Binary molecular compounds
The leftmost (or bottom-most) element on the periodic table goes first
… unless it’s oxygen, which always goes last
… unless oxygen is paired with fluorine, and then it’s first again
The name of the second element is given the “ide” suffix
Use Greek prefixes (mono, di, tri, tetra, etc.) to indicate number of atoms
… but don’t uses “mono” for first element
PCl5  phosphorous pentachloride
N2O3  dinitrogen trioxide

17. Chemical Nomenclature
Common names
Ionic compounds
Acids
Binary molecular compounds
Basic organic compounds
Alkanes
Alcohols
Organic acids