the history of atomic theory - mr. finke's science class -...
TRANSCRIPT
![Page 1: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/1.jpg)
The History of Atomic Theory
![Page 2: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/2.jpg)
Part 1: Democritus to Thomson
![Page 3: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/3.jpg)
An atom is the smallest particle that an element can be divided and still be that element.
For example the smallest particle of carbon is a single atom of carbon. If you divide it is no longer carbon anymore.
PIECES
OF
CARBON
CARBON
ATOM
![Page 4: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/4.jpg)
The diameter of a pinhead is 100,000 times smaller than
the diameter of a stadium. Likewise the diameter of the
nucleus of an atom is 100,000 times smaller than the
diameter of an atom
![Page 5: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/5.jpg)
If all the atoms in a penny were blown up to the size of a
grain of sand they would cover the entire state of
California
![Page 6: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/6.jpg)
No one has seen an atom or a dinosaur directly.
We know of their existence only by indirect
evidence. Our theories of both dinosaurs and
atoms has changed over time based on this
indirect evidence
![Page 7: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/7.jpg)
This model of the atom may look familiar to you. This is the Bohr model. In this model, the nucleus is orbited by electrons, which are in different energy levels. ◦ A model uses familiar ideas
to explain unfamiliar facts observed in nature. A model can be changed as new
information is collected.
![Page 8: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/8.jpg)
The atomic model has changed throughout the centuries, starting in 400 BC, when it looked like a billiard ball. →
![Page 9: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/9.jpg)
In this lesson, we’ll learn
about the men whose quests
for knowledge about the
fundamental nature of the
universe helped define our
views.
![Page 10: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/10.jpg)
The Greek word “atomos” means
“indivisible.”
![Page 11: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/11.jpg)
Democritus
(460 - 370
B.C.)
Democritus thought that matter is
like motion. It cannot be divided in
half forever. The tortoise and hare
would never finish the race if you
could keep dividing the distance to
the finish line in half forever. This
is just like matter. The atom cannot
be divided and still be the same
matter.
![Page 12: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/12.jpg)
This is the Greek philosopher Democritus who began the search for a description of matter more than 2400 years ago.
◦ He asked: Could matter be divided into smaller and smaller pieces forever, or was there a limit to the number of times a piece of matter could be divided?
400 BC
![Page 13: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/13.jpg)
His theory: Matter could not be divided into smaller and smaller pieces forever, eventually the smallest possible piece would be obtained.
This piece would be indivisible.
He named the smallest piece of matter “atomos,” meaning “not to be cut.”
![Page 14: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/14.jpg)
Named the atom
from the Greek word
“atomos” meaning
indivisible.
Wrote that atoms
were the smallest
unit of matter to
keep its identity.
![Page 15: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/15.jpg)
To Democritus, atoms were small, hard particles that were all made of the same material but were different shapes and sizes.
Atoms were infinite in number, always moving and capable of joining together.
![Page 16: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/16.jpg)
Atoms are small hard particles.
Made of a single material that’s formed into different shapes and sizes.
They are always moving
They form different materials by joining together.
![Page 17: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/17.jpg)
This theory was ignored
and forgotten for more than
2000 years!
![Page 18: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/18.jpg)
Aristotle was a very famous Greek philosopher who believed that matter could be divided into smaller and smaller pieces forever. He held a very strong influence on popular belief and his views on this were accepted for centuries.
Why weren’t Democritus’s ideas accepted?
![Page 19: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/19.jpg)
The eminent philosophers of the time, Aristotle and Plato, had a more respected, (and ultimately wrong) theory.
Aristotle and Plato favored the earth, fire, air
and water approach to the nature of matter.
Their ideas held sway because of their
eminence as philosophers. The atomos idea
was buried for approximately 2000 years.
![Page 20: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/20.jpg)
Two thousand years later a British chemist and schoolteacher brings back Democritus’s idea of the atom
He performed many experiments to study how elements join together to form new substances
He found that they combine in specific ratios (remember the electrolysis of water) and he supposed it was because the elements are made of atoms.
![Page 21: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/21.jpg)
In the early 1800s, the English Chemist John Dalton performed a number of experiments that eventually led to the acceptance of the idea of atoms.
![Page 22: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/22.jpg)
All matter is made up of atoms.
All atoms of the same element are the same.
Atoms combine in specific ratios.
There is nothing smaller than an atom.
![Page 23: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/23.jpg)
He deduced that all elements are composed of atoms. Atoms are indivisible and indestructible particles.
Atoms of the same element are exactly alike.
Atoms of different elements are different.
Compounds are formed by the joining of atoms of two or more elements.
![Page 24: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/24.jpg)
All substances are made up of atoms which are small particles that cannot be created, divided, or destroyed.
Atoms of the same element are exactly alike and atoms of different elements are different.
Atoms join with other atoms to form different substances
![Page 25: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/25.jpg)
This theory became one of the foundations of modern chemistry.
![Page 26: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/26.jpg)
J.J. Thomson is most famous for discovering that atoms are made of smaller negatively-charged particles called electrons.
Thomson’s discovery was the result of doing experiments with “cathode ray tubes”
![Page 27: The History of Atomic Theory - Mr. Finke's Science Class - …mrfinkescienceclass.weebly.com/uploads/8/3/4/3/83438… · · 2012-05-01The History of Atomic Theory . ... This model](https://reader034.vdocuments.mx/reader034/viewer/2022052608/5aa9d53b7f8b9a90188d5660/html5/thumbnails/27.jpg)
In 1897, the English scientist J.J. Thomson provided the first hint that an atom is made of even smaller particles.