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People desire order.
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People desire order. Agree?? Disagree??
Transcript of People desire order.
People desire order.
Agree?? Disagree??
People who have helped shape the world or
chemistry.
SIGNIFICANT EVENTS
Aristotle
The earliest Greek philosophers, like Aristotle, believed that all matter was
made of 4 basic elements; earth, air, fire, and water.
They did no “hands-on experiments” to prove their reasoning, yet this 4 element
model was thought to be fact for over two thousand years.
Democritus
He reasoned that all matter was made of tiny indivisible particles he called “atoms.”
It was over two thousand years before modern scientists proved him right.
Alchemists
European alchemists did hands-on investigations or centuries. Some believed they could change one form of matter into
another.Lead into gold, as an example.
Francis Bacon
He used the scientific method to investigate the physical world.
mmmm…..bacon
Robert Boyle
He made a very important contribution soon afterward when he expressed doubt about the ancient 4-element model. He
thought matter was made of elements and compounds.
Antoine Lavoisier
He defined elements as “pure substances that cannot be decomposed into simpler
substances.”
Allesandro Volta
He invented the “voltaic pile” a device we now would call a battery.
Humphry Davy
The English chemist decomponsedsubstances by using an electrical current
and succeeded in finding potassium, sodium, magnesium and many other
elements over a two-year period.
Michael Faraday
Davy’s assistant named this method “electrolysis”.
Faraday also invented many things we studied in our last unit.
Smart man.
Joseph Proust
He performed many experiments decomposing compounds into elements. He noticed a pattern, which I snow called
“The Law of Definite Proportions.”
As an example, pure water is made of…
Hydrogen Oxygen
They are always in the same proportion: 11% hydrogen and 89% oxygen.
John Dalton
He introduced a new way of talking about and explaining chemical facts and laws in
his atomic theory.His book provided relative masses of
20 elements to support his theory.
Dalton’s atomic theory gave chemists a great deal to think about. It provided a
quantitative basis for thinking about the structure of matter.
J.J. Thomson
He determined that currents were streams of negatively charged particles, later called
electrons.He proposed the “raisin bun” model of the atom. This was short lived…mostly due to
his student’s studies to test his theory.
Ernest Rutherford
He discovered the nucleus in an experiment using gold foil and alpha particles.
He later discovered the nucleus was composed of protons and neutrons.
J.J. Thomson was my teacher.
I’m smarter than him.
Ernest Rutherford
Considered to be the “Father of the Nuclear Age”. After he concluded his studies in the structure of the atom, he studied nuclear
reactions. He could induce a nuclear reaction in a stable element…
…paving the way for the atomic bomb.MIND BLOWN
Niels Bohr
He worked with Rutherford and discovered that electrons exist in levels or shells
around the nucleus. Each of these levels or shells have a different amount of energy.
I am NOT a bore!
Dmitri Mendeleev
Designed the first Periodic Table of Elements.
Clever man.
We’ll learn more about him later…
