Thales (600 B.C.)

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Thales (600 B.C.)
Water
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Xenophanes (500 B.C.)
Earth
Water
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Empedocles (440 B.C.)Four elements
Earth
(more commonly called dirt)
Water
Fire
Air
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Two Forces shape matter
Love Strife
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Democritus Athens, Greece 400 B.C.
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The smallest particles of matter are indivisible.
Since atomos is the Greek word for indivisible
I shall call these particles atoms.
Atoms cannot be destroyed, so there is
conservation of matter.
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Aristotle Athens, Greece 340
B.C.
Aristotle studied under Plato who also had
opinions on chemistry. However, Aristotle had
the most influence on the history of chemistry.
Besides chemistry, he also tackled physics,
biology, psychology, and logic.
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Its ironic that the theories of Aristotle which
were most accepted were also the most incorrect.
For example, he proposed and embraced the
mystical fifth element. It took chemists 2,000
years to recognize that there was no mystical
fifth element.
His theories that were most correct were mostly
ignored.
For example, he correctly classified dolphins as
mammals and not fish. It took 2,000 years for
biologists to accept this.
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First Table of the Elements
Dry
Hot
Cold
Wet
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• Fifth Element
• Quintessence
• Philosophers stone

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Fifth Element makes up the celestial bodies
Gold is the perfect metal.All other metals are
less perfect.
The fifth element is so divine that it can turn
the lesser (more base) metals into gold.
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Fifth Element
Elixir of life (a fountain of youth)
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Disagree with Democritus

• Matter does not consist of atoms
• Democritus said atoms cannot be divided. You
  cannot place restraints on the gods.

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Antoine Laurent Lavoisier France
1793

• Lavoisier has been called the father of modern
  chemistry.

• Started a system of chemical nomenclature that
  used ide, -ic -ous endings.

Examples Sodium chloride, Ferric oxide and
Ferrous oxide
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Antoine married the daughter of the tax
collector, which helped him pay for his expensive
laboratory.
Marie acted as a skilled lab assistant,
translator of English science publications, and
illustrator for Lavoisiers experiments
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Lavoisier

• When heated mercury turned red and absorbed 1/5
  of the air.

• The amount of active air consumed was the same
  as the amount of active air released later.

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Died quickly
Lived longer
Lived for a while
Oxygen
Azote
S O2 ? SO2 2SO2 O2 ? 2 SO3 SO3 H2O ? H2SO4
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Table of the Elements (33)
Antimony Arsenic Bismuth Cobalt Copper
Gold Iron Lead Manganese Mercury
Molybdena Nickel Platina Silver Tin
Tungstein Zinc
Lime Magnesia Barytes Argill Silex
Oxygen Azote Hydrogen Sulphur Phosphorus
Charcoal Muriatic radical Fluoric radical
Boracic radical
Argill (clay or alumpotassium aluminum
sulfate) Silex (silicon dioxide quartz Magnesia
(epsom saltsmagnesium sulfate) Lime calcium
oxide
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John Dalton England
1796
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Elements are composed of minute, indivisible
particles called atoms
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4. Chemical compounds are formed by the union of
two or more atoms of different elements.
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5. Atoms combine to form compounds in simple
ratios, such as 11, 12, 22, 13, and so forth.
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For example, if we decomposed 100 grams of water
using electricity, we always get this proportion
of mass.
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6. Atoms of two elements may combine in
different ratios to form more than one compound.
We call thisThe Law of Multiple Proportions
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Arranged from light to heavy by their relative
weights
Daltons Elements
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Johan Jacob Berzelius from Sweden
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Berzelius Symbols for Elements

• Older elements take the symbol from their Latin
  name.
• Fe comes from ferrum not iron.
• Instead of G for gold he wants Au from aurum.
• Instead of S for Silver he wants Ag from
  argentum.
• Newer symbols come from English names.
• O comes from oxygen.
• 2000 experiments over a ten-year period to
  determine accurate atomic masses for all the
  elements now known.

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John Newlands England
1867
Researchers had already began to arrange and
classify elements Metals vs. non-metals In
tables of increasing atomic weight
John Newlands from England had a different way to
arrange elements.
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Certain elements resembled one another in
behavior.

• Chlorine, bromine iodine
• violently corrosive
• form acids
• Lithium, sodium, potassium
• Unite violently with oxygen or water
• Oxides form caustic aqueous solutions

Every eighth element have similar
characteristics Li Be B C N
O F Na Mg Al Si P S
Cl K Ca ? ? As Se Br
I call this the Law of Octaves
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Lightest to heaviest.
Li BeBCNOF
NaMgAlSiPSCl
K Ca??AsSeBr
Li BeBCNOF NaMgAlSiPSCl
K Ca??AsSeBr
I call this the Law of Octaves because of its
similarity to musical octaves
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Law of Octaves
He presented his theory to the England Chemical
Society and was laughed at.
They said to arrange it alphabetically.
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Dmitri Ivanovich Mendeleev Russia
1871
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Periodic Law
Like Newlands, he used the lithium, sodium, and
potassium plus the chlorine family as guide posts
He also saw a periodic repeating of
characteristics. However on the third period, he
thought there were more than the seven elements
that Newlands listed.
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Gallium
Germanium
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Periodic Table of the Elements
The elements are ordered by the number of
protons they have in their nucleus
Atomic Number
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Periodic Table of the Elements
Elements are listed by increasing mass.
But grouped by reoccuring properties
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WHERE DID THE ELEMENTS COME FROM?
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End