By:
Jeffrey Fortin
Mark Fraser
Table of Contents:
 Ancient time- 450 A.D. , Demcritus, Thales, Leucippus
 1700- 1800, Sir Isaac Newton,
 1800 – 1875, John Dalton, Frederick Abel,
 1875 – 1900, Wihelm C. Roentgen, Marie Curie, J.J. Thomson
 1900 – 1915, Henri Bequerel, Erenest Rutherford, Erwin Schrodinger
 1915- 1950, Neils Bohr, Robert Milikan, Werner Hesienberg, James
Chadwick
 1950 – present, Bertrand Russell, J. Robert Oppenheimher, Bernard T.
Feld,
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Democritus
 460-370 bc
 Was born in Abdera in
Thrace
 Backed up Leucippus
theories, Atoms were
invisible, and had matter
 Also the only way to see
Atoms is when they
rearrange in a reaction
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Leucippus
Around for the first half of the 5th
century, he was the teacher of
Democritus. He believed
everything was composed of
atoms. Leucippus has no writings
that can be traced back to himself,
but can be through Democritus.
The only writing that can be traced
back to him is:
Nothing happens at random
(marten), but everything from
reason (ek logou) and by necessity.
– Leucippus,
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Thales
624-546 BC – born at Miletus
Through the understanding
of the earth, Thales came up
with water is the first
principal.
Also he discovered point ABC
in a circle make special cases
and can find the diameter of
a circle.
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1700-1800
 Sir Isaac Newton
 Antoine Lavoisier
 Humphry Davy
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Sir Isaac Newton
1643-1727
Sir Isaac Newton laid the
foundation of the atomic theory
with the different attraction in the
different stated atoms were in
weather it was gas liquid or a solid.
He also discovered calculus and the
first three laws of motion.
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Antoine Lavoisier
 1743-1794
 Developed the first
extensive list of elements
 Reformed chemical
nomenclature
 Recognized oxygen and
hydrogen
 Discovered that mass
may change shape or
form, but the mass
always stays the same
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Humphry Davy
1778-1829
Davy discovered alkali and alkaline
earth metals. He is also credited
with discovering chlorine and
iodine. He invented the Davy work
lamp which let miners work in
gaseous areas. This scientist also
discovered such elements as
sodium potassium, calcium,
magnesium, barium and boron.
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1800-1875
Frederick Abel
John Dalton
Jon Jacob Berzelius
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Frederick Abel
 1837- 1902
 Abel was a professor at the Royal Military Academy
 He was appointed to Chemist of the War Department
 Abel also invented Guncotton, which is a low order
propellant which lead to the development of gun
powder
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John Dalton
1866-1844
An English chemist who created
the:
Atomic Theory
1) All matter is made of atoms. Atoms are
indivisible and indestructible.
2) All atoms of a given element are
identical in mass and properties
3) Compounds are formed by a
combination of two or more different
kinds of atoms.
4) A chemical reaction is a
rearrangement of atoms.
This is what it looked like in His
new system of chemical
Philosophy
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Jons Jacob Berzelius
1779-1848
Berzelius came up with
chemical notation and, along
with Dalton, was considered
one of the founders of
modern chemistry.
He also discovered new
elements such as silicon,
selenium, thorium, cerium,
and lithium
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1875-1900
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Wilhelm C Roentgen
1845- 1923
He was a German Physicist
who detected
electromagnetic
radiation in the wave
lengths which is better
known as the X-Ray
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Marie Curie
1867-1934
Madam Curie is known for her
theory of radioactivity, and also for
discovering two new elements,
Radium and Polonium. She won
many awards including the Nobel
peace prize. She was also the first
female professor at the university
of Paris. Her life was unfortunately
cut short bye a street car accident
involving a horse drawn vehicle.
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JJ Thomson
1856-1940
He won the Nobel prize for his
discoveries involving electrons and
isotopes, along with his studies of
the conductivity of electricity in
gasses.
He was knighted in 1908 and
became the master of trinity
college in 1916 were he continued
to work until his death.
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1900-1915
 Herni Becquerel
 Ernest Rutherford
 Albert Einstein
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Herni Bequerel
 1852-1908
 Becquerel was a major
contributor to the
discovery of X-Rays and
radioactivity
 He was also the third in his
family to occupy the chair
at the museum national
d’histoire Nuturella
 Adding to his list of
accomplishments, he was
award the Nobel prize with
Marie and Pierre Curie
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Ernest Rutherford
1871-1937
Known as the father of nuclear
physics, he conducted the gold foil
experiment which proved that the
positively charged atoms were
being deflected, some only a few
degrees but a couple up to ninety
degrees. This proved that there is a
small, dense center in an atom
known as the nucleus. He was
awarded the Nobel peace prize for
his outstanding work in the year
1908.
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Albert Einstein
 1879-1955
 He was a winner of the Nobel
peace price and was a key
player in the Manhattan
Project, although he was
opposed to use of the atomic
bomb in war.
 Einstein was also well known
for his work involving the
photoelectric effect, which
can be described as when
matter absorbs electron
magnetic radiation, resulting
in electrons being emitted
from the object.
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1915-1950
 Niels Bohr
 Werner Heisenberg
 Erwin Schrodinger
 James Chadwick
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Neils Bohr
Life
 1885-1962
 He is know for the
development of the atomic
structure and quantum
mechanics
 He received the Nobel peace
prize in 1922
 He also worked on the
Manhattan project
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Werner Heisenberg
1901 -1976
He received his Nobel peace prize
for setting forth the matrix
formulation of quantum
mechanics. He was involved with
the Nazis and was in their
“Uranium Club” Heisenberg was
also in charge of the Reich
Research Council. He was one of
ten scientists that were arrested
after WWII. He then settled in a
British occupied zone in Germany
and was the head of the Kaiser
Wilhelm Institute For Physics.
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Erwin Schrodinger
1887-1961
He received the Nobel peace prize
for his contributions in Quantum
Mechanics. He also applied atoms
to everyday life in his Schrodinger
Cat Through experiment. He also
published the Annals der Physiks
paper which was considered one of
the most important of the 20th
century.
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James Chadwick
 1891- 1974
 He was award the Nobel
peace prize in 1935
 He was awarded this for
his discovery of
Neutrons
 He did a major part of
his studies at Cambridge
college
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1950- present
 J. Robert Oppenheimer
 Bernard T. Felds
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J. Robert Oppenheimer
 1904-1967
 The father of the Atomic
Bomb
 In 1954 during the Red
Scare, Oppenheimer was
revoked of his rights to
write about physics, and
his security clearance was
revoked
 When JFK was in office he
was awarded the Enrich
Fermi Award as a gesture of
political rehabilitation
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Bernard T Feld
1919-1993
He worked on the Manhattan
Project but then was appointed
to the international conceal to
remove nuclear weapons form
the world. Also worked at the
Massachusetts Institute of
Technology. “ I was involved in
the original sin, and I have
spent a large part of my life
atoning for it. - Bernard T. Feld ”
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Atomic Models
 Small, sphereical, solid, indivisible model
 Electron cloud model
 Plum Pudding model
 Rutherford-Bohr model
 Planetary model
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Small, spherical,
solid, indivisible
model
In early times, before the discovery
of protons, neutrons, or electrons,
popular belief was that the smallest
partical of matter was a tiny, small,
solid partial. Nothing else was
known as far as the nucleus is
concerned.
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Plum Pudding
model
The design was proposed by J.J.
Thomson in 1906. The discovery of
the nucleus had yet to be made, so
naturally this component of the
atom was lacking from Thompsons
model. What he did include,
however were “corpuscles,”
Thompsons name for electrons,
that he depicted as plums in his
model. The pudding was a
positively charged area of mass
which balanced out the negative
charge of his plum-like
“corpuscles”.
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The planetary model of the atom
 Developed by Neils Bohr,
in his model the protons
and neutrons are located
in the small, dense
nucleus, while the
electrons orbit around
them. The scale is
disproportionate,
however, because of the
fact that the atomic
radius is roughly 1000
times that of the nucleus
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Rutherford-Bohr
model
Developed by Ernest Rutherford
and Neils Bohr, this model was an
important step in understanding
the structure of the atom.
Rutherford's gold foil experiment
led him to the discovery of the
dense central region within a
primarily entry space in each atom.
He also concluded that since
positively charged partials bounced
back, the central region must have
a positive charge. These two
scientists created this model in
such a way that the electrons travel
around the nucleus in an orbit al
fashion. There are different levels
upon which these negatively
charged partials travel. The further
away from the nucleus, the more
energy they have. Though not
perfect by today’s standards, the
model was a breakthrough at the
time
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Electron Cloud
Model
Based upon the work of a number
of scientists including Rutherford,
Bohr, Heisenberg and Schrödinger,
the Electron Cloud Model is a
compilation of ideas. Rutherford's
contribution is the small dense
nucleus within a cloud. The
electron cloud surrounding it is
made up by ideas form Bohr and
Heisenberg. Bohr had the idea
that electrons moved around the
nucleus while Heisenberg figured
out that the only way to describe
where they are is through probity
distribution. His concept is
involved in quantum mechanics
where Schrödinger comes into play.
The electron cloud is a region were
the electrons could be found but
doesn’t specify where they are.
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Bibliography
 “Language of Physics.” Dictionary and Research Guide. 2001
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2008 Enlexica. November 1, 2008. <http://www.123expscience.com/t/01554053557/>
“Understanding Radiation in Your Life, Your World.” US
Environmental Protection Agency.
<http://www.epa.gov/rpdwebOO/understand/rutherford.html>
“The Cloud Model.” Science Joy Wagon. 1999
<http://www.regentsprpe.org/Regents/physics/phys05/catomod
el/cloud.html>
“Who Came Up With The Electron Cloud Model of the Atom?”
WikiAnswers. Answers Corporation 2008.
<http://wiki.answers.com/Q/Who_came_up_with_the_electron
_cloud_model_of_the_atom>
Wikimedia Foundation, Inc. <http://www.wikipedia.org/>
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