Download Color and Light Write five sentences about this picture.

Atomic Theory
John Dalton

Four Part Theory adopted as basis for the
Modern Atomic Theory
1. All things are made of atoms
2. Similar atoms are similar and different atoms are
different
3. Atoms combine to form molecules
4. Chemical reactions do not alter atoms
Electrons
J.J. Thomson



English physicist
Worked on electricity,
magnetism, and
charged particles
Discovered
ELECTRON
Electrons
J.J. Thomson



Used a cathode ray tube
and experimented with
the beam of energy.
Based on deflection with
magnets and electricity,
he assumed the beam
was made of negative
particles.
Discovered electron
Electrons
J.J. Thomson



Plum Pudding Model
of Atom
Electrons as discrete
particles
Remaining mass an
unorganized glob.
Nucleus
Ernest Rutherford



Used alpha particles
(Helium atoms) fired at a
piece of gold foil.
Deflections of the
particles made him
assume that there was a
massive particle at the
center of the atom.
Discovered Nucleus
Gold Foil Experiment
Neutron
James Chadwick



Calculated the mass
of similar atoms.
Recognized isotopes.
First to recognize the
extra mass in the
nucleus was a neutral
particle…Neutrons
Splitting the Atom
Lise Meitner


Calculated the energy
in “Binding Energy” in
the nucleus.
First to recognize the
disintegration of a
nucleus
Radiation
Andre Becquerel

Discovered radiation
Marie Curie

Early research in
radiation.
Ions and Isotopes
Three particles in the atom
Proton
Neutron
Electron
Charged
+1
Neutral
0
Charged
-1
Has Mass
1 AMU
Has Mass
1 AMU
No Mass
0 AMU
Ions
Ions have Three Characteristics
1.
Ions are charged particles
2.
Protons not equal to electrons
3.
Can be positive or negative
Ions
Calculate the Charge
A Carbon atom with 6 protons, six neutrons and
six electrons
(6 protons x (+1)) = +6
(6 neutrons x (0)) = 0
(6 electrons x (-1)) = -6
Sum = 0 (no charge)
Ions
Calculate the Charge
A Carbon atom with 6 protons, six neutrons and
four electrons
(6 protons x (+1)) = +6
(6 neutrons x (0)) = 0
(4 electrons x (-1)) = -4
Charge = +2
Isotopes
Isotopes are all about Mass
Compare protons and neutrons
If protons and neutrons are NOT equal, then the
atom is an isotope.
Isotopes
Calculate the Mass
A Carbon atom with 6 protons, 6 neutrons
and 4 electrons
(6 protons x (1 AMU)) = 6 AMU
(6 neutrons x (1 AMU)) = 6 AMU
(4 electrons x (0 AMU)) = 0 AMU
Mass = 12 AMU
Isotope Notation
Mass = Protons + Neutrons
60
28
Atomic Number or
Number of Protons
Charge
4+
Ni
Element
Ions and Isotopes
19
9
F
15
7
1-
N
38
19
3-
68
33
K
1+
As
60
28
5+
Ni
36
18
4+
Ar
Ions and Isotopes
12
5
37
17
B
3-
Cl
46
23
1-
59
29
V
4+
Cu
30
14
2+
72
36
Si
4+
Kr
Mole
The mole is a term to describe quantity.
1 dozen = 12 things
1 gross = 12 dozen = 144 things
1 mole = 602,000,000,000,000,000,000,000 things
6.02 x 1023 things
Mole
The mass of one mole of an element is the atomic mass.
1 mole of Carbon = 12 grams
1 mole of Sodium = 23 grams
1 mole of Carbon atoms is 6.02 x 1023 atoms
1 mole of Sodium atoms is 6.02 x 1023 atoms
One is a measure of “mass”
The other is a measure of “how many”
19
9
1-
F
What is the mass of 2 moles
of this element?
How many atoms are present in
2 moles of this element?
Is this atom an ion an isotope
both or neither?
Periodic Table
Objectives

Element Names and Symbols

Periodic Table Geography

Characteristics of Major Groups
Periodic Table
Dimitri Mendeleev
Organized the
Periodic Table
 Made predictions
about the elements
yet to be discovered

Periodic Table
Alkali Metals
Alkali Metals: Highly reactive
elements that combine with many
nonmetals to form ionic solids (salts).
They also form compounds with
oxygen that dissolve in water to
create solutions that are strongly
alkaline.
Alkaline Earth Metals
Alkaline Earth Metals: Very reactive
elements that form ionic compounds
with nonmetals. Many of their oxygen
compounds are found in deposits in
the ground.
Transition Metals
Transition Metals: Generally less reactive than the alkali
and alkaline earth metals, these elements vary in physical
and chemical properties. Many form important alloys with
one another and other metals. Several of the transition
elements can form more than one positive ion. For
example, iron can form more than one ion, Fe 2+ and Fe 3+.
Halogens
Halogens: Reactive elements that
form compounds known as halides.
Several halogens including chlorine,
fluorine and iodine, have important
applications in everyday life.
Noble Gases
Noble Gases: Elements are generally not
reactive; however, the heavier noble gases
can react with a few halogens. These
elements have generally complete electron
shells. They are gases at very low and very
high temperatures.
Metalloids
Metalloids: Elements that
display characteristics of both
metals and non-metals. They
are only partial conductors of
electricity and are therefore
also known as semiconductors.
Non-Metals
Non-Metals: Elements that do
not display characteristics of
metals. They are not shiny,
they do not conduct electricity,
and they are not malleable
Metals: Elements that display
characteristics of metals. They
are shiny, they conduct
electricity, and they are
malleable