AP Ch2: Atoms, Molecules
and ions
History of Chemistry
• 400 B.C: Democritus
(greek philosopher)
hypothesizes that all
matter is composed of
tiny particles called
atoms.
Atoms vs Hyle
• 1500’s: Georg BauerGermany, develops
systematic
metallurgy. How to
extract metals from
raw ore.
Robert Boyle-1st true chemist
• Wrote: The Skeptical
Chymist
• Developed P1V1 =
P2V2 Boyle’s Law
Joseph Priestly
• 1700’s: English clergyman discovers oxygen!
Priestly ROCKS!
Antoine Lavoisier
• 1700’s: French
chemist, uses
combustion reaction
to verify the law of
conservation of mass,
mass cannot be
created nor destroyed
by ordinary chemical
reactions.
Joseph Proust
• Proust’s Law: “The Law of Definite Proportions:
A given compound always
contains exactly the same
proportions of elements by mass”
Example: CuCO3 is always 51% Cu, 10% C and
39% O, by mass.
John Dalton….THE MAN!
John Dalton 1
• Formulates the law of multiple proportions:
Elements can combine to form a series of
compounds.
Example:
N2O dinitrogen monoxide
N + O2
NO nitrogen monoxide
NO2 nitrogen dioxide
NO1/2 cannot form
John Dalton 2
•
Formulates Atomic Theory:
1)
Each element is made up of tiny particles called
atoms.
The atoms of a given element are identical.
Chemical compounds are formed when atoms come
together, in simple whole number ratios.
Chemical reactions involve the reorganization of the
atoms; combined, separated or rearranged.
2)
3)
4)
1808: Gay-Lussac
• Develops:
P1/T1 = P2/T2
1903: J.J. THOMSON
• Discovers the
electron, using his
famous Cathode Ray
Tube (CRT), which
turns out to be a
primitive TV or
computer monitor.
He also calculated the
charge of electron to
be -1.76 x 108
Coulombs per gram.
1909 Millikan finds the charge of an
electron.
• Robert Millikan finds the charge on the
electron to be -1.6 x 10-19 Coulombs
Robert Millikan’s Oil Drop Experiment
CRT and TV
1900’s Eugene
Goldstein discovers
that beams of
particles travel in the
opposite direction as
cathode rays. These
particles are protons.
1911 Ernest Rutherford
• Rutherford discovers
the nucleus of an
atom, using his
famous gold foil
experiment. His
native New Zealand
put his image on
money.
Rutherford’s Gold Foil Experiment
Rutherford’s Gold Foil Experiment
James Chadwick
• Chadwick,
Rutherford’s
assistant, later made
the observation that
when gold nuclei are
radiated with alpha
particles, they
sometimes emit
particles, which are
not affected by a
charge. This was the
discovery of the
neutron.
Nuclear Radiation
Type
Alpha
symbol
a
make-up
2p+ & 2no
mass
4 amu
Beta
B
high speed
electron
1/1840 amu
Gamma
g
high energy
photon
0 amu
Positron
e+
beta antiparticle 1/1840 amu
penetrating power
low
medium
high
high
Penetrating Power
Periodic Table: The Basics
Classes of elements to know:
•
•
•
•
•
•
•
•
•
Group 1: Alkali metals
Group 2: Alkaline-earth metals
Groups 3-12: Transition Metals
B, Si, As, Te, Ge, Sb are metalloids
Group 17: Halogens
Group 18: Noble Gases
Elements #57-70: Rare-Earth Metals
Elements #89-102: Radioactive Series
*All elements with an atomic number greater
than 83 and Tc have all radioactive isotopes.
• **All elements on the periodic table on the wall
which are outlined are synthetic.
Nomenclature: Naming Chemical
Compounds
•
1)
2)
3)
4)
5)
The types of chemical compounds you need to
know for this chapter:
Covalent binary
Ionic binary
A) singlevalent cation (s-block)
B) multivalent cation (transition metal)
Ionic ternary (containing a polyatomic ion)
Ionic ternary hydrates
Acids
Binary Covalent: prefix___ prefix___ + ide
(2 nonmetals)
# of atoms
1
2
3
4
5
6
7
prefix
monoditritetrapenthexhept-
examples
CO2
CCl4
NO2
N2O5
P2O3
SO3
SO2
Binary ionic: cation anion+ide
(metal + nonmetal)
Formula
KCl
Name
magnesium chloride
NaBr
lithium oxide
Al2O3
calcium sulfide
BeF2
strontium nitride
NaH
Ionic w/ a multi-valent(transition metal) cation
• The oxidation number of the cation is always given in roman
numerals, in parethesis.
Common cations to memorize:
• Cr 2+ = chromium (II) aka: chromous
Cr 3+ = chromium (III) aka: chromic
• Fe 2+ = iron (II) aka: ferrous
Fe 3+ = iron (III) aka: ferric
• Co 2+ = cobalt (II)
Co 3+ = cobalt (III)
• Ni 2+ = nickel (II)
Ni 3+ = nickel (III)
• Cu + = copper (I) aka: cuprous
Cu 2+ = copper (II) aka: cupric
• Sn 2+ = tin (II) aka stannous
Sn 4+ = tin (IV) aka stannic
• Pb 2+ = lead (II) aka plumbous
Pb 4+ = lead (II) aka plumbic
Indicates the most common form
Hydrates:
• Name ionic compound + _______ hydrate
(prefix)
Example:
CuSO4 . 5 H2O copper (II) sulfate pentahydrate
Acids
Binary acids = hydro-_____-ic acid
Ternary acids(oxyacids):
Name anion, ite = ous acid
OR
Name anion, ate = ic acid
POP QUIZ!!!!!
• Name the following compounds:
Na2S
Fe(NO3)3
Mg(C2H3O2)2
NH4NO2
K2CO3
S2O5
CuCl
Zn(ClO3)2
CuCl2
Zn(ClO4)2
CuCl2.3H2O
Zn(ClO2)2
H2CO3
Zn(ClO)2
N2O3
HCl
HClO2
HClO4
HClO3
END OF CHAPTER 2