History of Chemistry
Teresa Galloway
JFKS
If I have seen
further it is by
standing on the
shoulders of
giants.
Sir Isaac Newton
Chemistry through the Years
- 18th Century: Gas
Chemistry
- 19th Century:
Organic Chemistry
- 20th Century:
Nuclear Chemistry
- 21st Century:
Quantum
Chemistry
More on the Periodic Table:
• Daniel Radcliffe sings the Element Song
Historical Outline of Atomic Theory
Website
• History Website
• Corrosion Doctors Website
Greek View
 Democritus: 470-380 BC
Coined the term “atom”
 Aristotle: 384-322 BC
Four Element Concept
Ancient Philosophers
21 Centuries Later………..
• Robert Boyle: (1627-1691 Ireland)
• In 1665 in Oxford, along with his assistant
Robert Hooke devised the vacuum
chamber
• First prominent scientist to perform
controlled experiments and publish his
work
• Boyles Law: P1V1 = P2V2
Antoine Lavoisier (1743-1794 France)
• First person to make good use of the
balance changing chemistry from
qualitative to quantitative
• Disproved Phlogiston Theory/instead
proposed Combustion Theory
• Law of Conservation of Mass
• Beheaded by guillotine in 1794
• Antoine Lavoisier YouTubeVideo
Joseph Proust (1754-1826 France)
• Law of Constant Proportions 1799
– The proportions of the components of a
chemical compound are always the same no
matter how it is prepared
– became more clear to scientists in 1803 with
the help of John Dalton
– FYI: First to identify the sugar that comes
from grapes as glucose
Amadeo Avogadro (1776-1856 Italy)
• Avogadro’s Hypothesis: 1811
• At the same temperature and pressure,
equal volumes of gases contain the same
number of molecules
• Extremely radical for the time period, was
not accepted for another 50 years
(Karlsruhe Conference 1860)
Amadeo Avogadro
A Mole is a Unit
John Dalton (1766-1844 England)
• Daltons Atomic Theory: (1803)
• Elements are made of tiny particles called atoms
• All atoms of the same element are identical
(later to be revised)
• The atoms of a given element are different from
those of any other element
• Elements combine to form compounds
• Mass is neither created or destroyed in a
chemical reaction, but can be rearranged.
Events Leading to the Periodic Table:
• Johann Dobereiner (1817)
• Law of Triads
• Proposed that nature contains triads of
elements where the middle element has
properties that were an average of the
other two members when ordered by the
atomic weight (Li,Na,K)
John Newlands (1863 England)
• Law of Octaves
• Any given element will exhibit analogous
behavior to the 8th element following it in
the periodic table.
Dmitri Mendeleev (1834-1907
Russia)
• Late 1860’s, arranged the 63 known
elements (known by atomic weights) into
groups based on chemical and physical
properties
• Where a gap existed, he predicted a new
element would be found and its properties,
Ga (1875), Sc (1879), Ge (1886) were
found during his lifetime
• YouTubeVideo on Mendeleev
Lothar Meyer
• Meyer’s 1864 textbook included an
abbreviated version of the periodic table
consisting of appx ½ of the elements listed
in order by atomic weight and
demonstrated periodic valence changes
as a function of atomic weight.
• In 1868 he constructed an extended table
and gave it to a colleague to evaluate
Meyer vs Mendeleev
http://www.chemheritage.org/discover/che
mistry-in-history/themes/the-path-to-theperiodic-table/meyer-and-mendeleev.aspx
Discovery of the Noble Gases
• 1904 Chemistry Nobel Prize for Ramsey
and physics for Rayleigh
• Lord Rayleigh was studying nitrogen in the
air and noted that the weight was always
greater than that of N2 in other compounds
thus Argon was found.
• Discovery of the other noble gases then
quickly followed
Glenn Seaborg
• Starting with his discovery of plutonium in
1940, he discovered all the transuranium
elements (94-102)
• He reconfigured the periodic table by
placing the actinide series below the
lanthanide series
• 1951 received Nobel Prize in chemistry for
his work
• Glenn Seaborg and the discovery of 10
elements
ATOMIC STRUCTURE
• The Atom Song
J.J. Thomson
British 1856-1940
• Nobel Prize in physics 1906
• 1871 became a professor at the
Cavendish Laboratories in Cambridge
England
• Experimented with electrical currents
inside empty glass tubes (cathode rays)
• Bold proposal that these mysterious rays
are streams of particles much smaller
than atoms
• Proposed the first model of the atom with
subatomic particles
• Credited with the discovery of the electron
based from his work with cathode ray tubes
• Plum Pudding Model: the atom is made up
of a positively charged pudding with
negative electrons distributed throughout to
neutralize the atom
• cathode ray tube
• Sir JJ Thomson
Robert Millikan Oil Drop
Experiment
• Performed in 1909 determined the size of
the charge of an electron
• Oil Drop Experiment
Ernest Rutherford
• New Zealand, 1871-1937, physicist
• Awarded a scholarship to Cambridge
University (1894) where he was influenced
by JJ Thomson to study the recently
discovered x-rays
• Coined the terms: alpha, beta and gamma
rays, half-life, proton
• Given credit for the proton, and nucleus
• 1907 went to Univ. of Manchester to work
with Hans Geiger
• 1908 received Nobel Prize in chemistry for
his work with radiation and the atomic
nucleus
• Appx1909 discovered the atomic nucleus
and proposed a model of the atom
• Gold Foil Experiment (1909)-the atom is
mainly empty space through which
electrons move and there is a tiny dense
region “nucleus” centrally located that
contained all of an atom’s positive charge
• Rutherfords Gold Foil Experiment
• Another Look at Gold Foil
H G J Moseley
• Died at the age of 27, shot through the
head by a Turkish bullet at Gallipoli in
1915.
• “ein schwerer Verlust für die
Naturwissenschaften”
• Studied the frequency of x-rays given off
by cathode ray tubes when electrons strike
the anode.
• Found that there was a relationship
between the frequencies (v) of the x-rays
given off by the cathode ray tube and the
atomic number of the metal used to form
the anode.
• Conclusion: The atomic number was
equal to the positive charge (charge on the
nucleus) of an atom. (1914)
• This then caused the periodic table to be
reorganized based on atomic number of
the element, not atomic weight.
James Chadwick
1891-1974, British
• 1911 spent two years working with Ernest
Rutherford
• Main studies were with radioactivity
• Along with Rutherford and others noticed
that the proton did not account for all the
mass of an atom, that the atomic mass
was always more than the atomic number
• Hypothesis of the time was that there was a
proton-electron pairing in the nucleus
making up for the difference of the mass
• Influenced by the work of Frederick and
Marie –Joliot Curie and their work with
radiation
• 1932 neutron discovered to be the “neutral”
particle that weighed 0.1% more than the
proton accounting for the mass
• 1935 Nobel Prize for his work
• Bill Nye the Science Guy: Atoms
Neils Bohr
• Quantum Mechanics The Structure of
Atoms
Niels Bohr 1885-1962, Danish
• 1922 Nobel Prize in physics for his work
on the atomic structure
• Studied under Rutherford in Manchester
• Expanded Rutherfords theory that
electrons could travel in certain orbits and
that the outer orbits determined the
chemical properties of the atom
• Also described the way atoms emit
radiation by suggesting that if an electron
gains energy it can jump from ground state
to a higher energy level “excited” state.
And when the electron loses energy and
falls back to a lower energy level, it gives
off a photon of light.
• 1939 visited the USA and relaid news that
German scientists were working on
splitting the atom, which spurred the
creation of the Manhattan Project
Werner Heisenberg 1901-1976,
German Physicist
• Influenced by the work of James Chadwick
• 1927 Uncertainty Principle: It is
impossible to know both the exact location
& velocity of an electron at any given time.
• Nobel Prize in Physics in 1932 for the
creation of quantum mechanics, the
application which has led among other
things to the discovery of the allotropic
forms of hydrogen
Ich bin Werner Heisenberg
Where are we today?
Quantum Mechanics