What is simplified in this picture?
TheThompson: Discovery of the
Electronthe Electron (Thomson)
• Cathode Ray Tube
• Charged particles produced (affected by
magnetic field)
• Concluded that atom must have positive and
negative parts
• Electron – negative part of the atom
• Only knew the e/m ratio
• Plum Pudding Model
Charge and Mass of the Electron
(Millikan)
• Oil drop experiment
• Determines charge on electron (uses electric
field to counteract gravity)
• Quantized
• e = 1.602 X 10-19 C
• m = 9.11 X 10-31 kg
The Nucleus (Rutherford)
• Gold Foil Experiment
• Discovers nucleus (disproves Plum Pudding
Model)
• Planetary Model
Atoms:Basic Facts
Three particles
Particle
Charge
Mass
Proton
+1
~1 g/mol
Electron
-1
0.00055
g/mol
(1/1837)
Neutron
0
~1 g/mol
Photo of a single Barium atom
Atoms:Basic Facts
1. Size – Measured in Angstroms
1 A = 1 X 10-10 m
1 Cl atom = 2.0 A
5 million Cl atoms can be lined up in 1 mm.
Atoms:Basic Facts
1. Mass – grams/mole
H = 1.00794 grams/1 mole
1.00794 g/6.022 X 1023 atoms
C = 12 g/mol
Isotopes
1. Isotopes – Atoms with the same # of protons,
but different # of neutrons
Copper-63
29 p 34 n
Copper-65
29 p 36 n
2. Atomic Mass –weighted average of all the
isotopes
p
n
E
16
16
16
12
17
16
18
16
12
19
18
10
18
13C
90Sr
24Mg
Ions
1. Cation – Positive Ion
2. Anion – Negative Ion
3. Review Common Charges
P
ClO2-
Mg+
Mg2+
N
E
Stable vs. Unstable Nuclei
Nuclear Changes
1. Most nuclei are stable – do not change
2. Some nuclei are unstable (radioactive)
•
•
•
Change into a different nucleus (decay)
Spontaneous process – happens naturally, by itself
Releases radiation
Only nuclear reactions can change a nucleus.
No chemical process can
Radium

Radon
+ Radiation
Decay
-New element and alpha, beta, or gamma
-lost mass becomes kinetic energy
Alpha particle Helium nucleus
Types
of
Nuclear
Radiation
4
( 2He)
Beta particle
(0-1e)
Gamma rays

Positron
(0+1e)
2 p+
2n
fast-moving electron.
ehigh energy electromagnetic
radiation
positive electron (anti-matter)
What Stops Radiation
Paper
Alpha
()
Beta ()
Gamma
()
Al Foil
Lead.
Wood
Iron,
Concrete
Decay Equations
Alpha Decay
238 U  4 He +
92
2
234 Th
90
Beta Decay
234 Th  0 e +
90
-1
234 Pa
91
Decay Equations
Gamma Decay
Occurs with alpha and beta decay
No change in atomic mass (gamma radiation has
no mass 00)
Decay: Ex 1
What product is formed when radium-226
undergoes alpha decay?
226 Ra
88

4 He
2
+
Decay: Ex 2
What element undergoes alpha decay to form
lead-208?

4
2He +
208
82Pb
Decay: Ex 3
What isotope is produced when thorium-231 beta
decays?
90Th 
231
0
-1e
+
Write the equation that describes oxygen-15
undergoing positron emission.
Which nuclei are radioactive (unstable)
1. All elements have at least one radioactive
isotope
2. All isotopes of elements heavier than Lead (82)
82
Pb
At least one
radioactive isotope
207.2
All isotopes are
radioactive
Transmutation
• Rutherford(1919) – First successful alchemist
14 N + 4 He  17 O + 1 H
7
2
8
1
• Modern methods
– Particle Accelerators (Cyclotrons)
– Use neutrons or other elements (creation of
transuranium elements)
Periodic Table
1.
2.
3.
4.
5.
Dmitri Mendeleev – 1869
Used atomic mass (modern is by atomic #)
Period – Across
Group – Down
Metals
Non-Metals
Metalloids - Semiconductors
Periodic Table
Group 1
Alkali metals
Group 2
Alkaline earth metals
Transition Metals
Group 7
Halogens
Group 8
Noble Gases
Lanthanides
Actinides
Discuss placement of Lanth/Act
Average Atomic Mass
1. Atomic Mass – Weighted Average of all
the isotopes
Average Atomic Mass
Calculate the ave atomic mass of Boron if it
exists as 19.90% Boron-10 (10.013 g/mol)
and 80.10% B-11 (11.009 g/mol)?
(Ans: 10.811 g/mol)
Mixing Elements
Ionic = Metal + Non-metal (NaCl)
Molecular = Non + Non (CH4)
Alloy = Metal + Metal
•Stainless steel (Fe/Cr)
•Brass (Cu/Zn)
•Bronze (Cu/Sn)
Ionic vs. Molecular
Ionic Compounds
Start w/ Metal
Stealing of Electrons
Clumps of Ions(crystals)
Called Salts
No prefixes, may need
Roman #
Molecules
Two Non-metals
Sharing of electrons
Separate Molecules
Shapes (tetrahedral, etc…)
Polar and Non-Polar
Molecules (H2O vs CH4)
Prefixes
Ionic Solids
Ionic vs. Molecular
Ionic or molecular?
HCl
CO2
VO3
H2O
BaF2
What ionic compound would form between:
Ba and Cl
Ba and Te
Al and S
Fe3+ and O
Fe2+ and O
H He
Al
Naming Ionics
I. Binary Compounds
Gr I and Gr II metals (and Aluminum)
NaCl
BaO
Al2O3
magnesium bromide
aluminum sulfide
potassium oxide
Naming Ionics
I.
Compounds with Polyatomics
Sodium hydroxide
Sodium carbonate
Aluminum Sulfate
NaNO3
Ca(OH)2
(NH4)3PO4
Mixed Examples
Magnesium Sulfide
Magnesium Sulfite
Magnesium Sulfate
Lithium Phosphide
Lithium Phosphate
Ba(ClO3)2
BaCl2
Roman # Ionics
1. Example
Fe(II)and oxygen
Fe(III) and oxygen
How do we distinguish?
2. Metals which have multiple oxidation states
Transition and post-transition metals
Iron (III)Bromide
Tin(II) nitrate
Cobalt(III)Oxide
CoCl2
MnO2
Ru2(SO4)3
VO3
Mixed Examples
Calcium Bromide
Chromium (III)Nitrate
Aluminum Sulfate
Iron(III)Carbonate
Li2S
CoCl2
Ti3N2
Mg(NO2)2
Magnesium Sulfide
Magnesium Sulfite
Magnesium Sulfate
Mn2(SO4)3
Lithium Phosphide
Lithium Phosphate
Ba(ClO3)2
Copper(II)nitrate
Household Ionics
Many ionic compounds are called salts
CaCl2
– Calcium Chloride (Quik-Joe)
NaHCO3 – Sodium bicarbonate(Baking soda)
CaCO3
– Calcium Carbonate(Chalk, antacid)
NaOH
- Sodium Hydroxide (Drano)
MgSO4 – Magnesium Sulfate(Epsom Salts)
All big clumps (crystals) of Ions
Naming Molecules
Prefixes
mono
hexa
di
hepta
tri
octa
tetra
nona
penta
deca
May skip “mono” for first element
CO
CO2
Cl2O7
SF6
Chlorine dioxide
Diphosphorus tetroxide
Carbon tetrachloride
Naming Molecules
Household Molecules
H2O
HCl
NH3
H2SO4
HC2H3O2
Review of all naming
CS2
N2O
NaI
PCl5
FeF2
HgI2
K2CO3
NO3
Ba(OH)2
Calcium Chloride
Silicon Dioxide
Copper(II)Carbonate
Magnesium Phosphate
Dicarbon Octahydride
Chromium(III)Oxide
Dihydrogen Monoxide
Acids
1. Binary Acids
HCl
HF
H2S
hydrochloric acid
hydrofluoric acid
hydrosulfuric acid
Acids
2. Oxoacids
HClO4
HClO3
HClO2
HClO
Acid
perchloric acid
chloric acid
chlorous acid
hypochlorous acid
Ion
perchlorate (ClO4-)
chlorate (ClO3-)
chlorite (ClO2-)
hypochlorite (ClO- )
Examples
HCN
HNO3
H2SO4
H2SO3
Examples
HNO2
HI
H3PO4
H3CO3
HClO3
H2
N2
O2
F2
Cl2
Br2
I2
Hydrogen
Nitrogen
Oxygen
Fluorine
Chlorine
Bromine
Iodine
(H(N3(O2(F(Cl(Br(I-
Hydride)
Nitride)
Oxide)
Fluoride)
Chloride)
Bromide)
Iodide)
26
1)Xe-130 has one more neutron
50)
1)Molecular PF5, SCl, N2O4
Ionic NaI Ca(NO3)2, FeCl3, LaP, CoCO3
32. 85.47 g/mol
56.a) CuBr2 b) Fe2O3 c) Hg2CO3
d) Ca3(AsO4)2
e) (NH4)2CO3
58. Na2O
CaO
FeO
Al2O3
NaNO3
Ca(NO3)2 Fe(NO3)2 Al(NO3)3
Na2SO4 CaSO4
FeSO4
Al2(SO4)3
Na3AsO4 Ca3(AsO4)2 Fe3(AsO4)2 AlAsO4
64.a) Cu2+ b) Ag+
c) Al3+
d) Co2+
e) Pb2+
1. 85.47 g/mol
2. Cu2+
Ag+
Al3+
Co2+
Pb2+
S2SO42ClO3OHCO32-