Loading presentation...

Present Remotely

Send the link below via email or IM

Copy

Present to your audience

Start remote presentation

  • Invited audience members will follow you as you navigate and present
  • People invited to a presentation do not need a Prezi account
  • This link expires 10 minutes after you close the presentation
  • A maximum of 30 users can follow your presentation
  • Learn more about this feature in our knowledge base article

Do you really want to delete this prezi?

Neither you, nor the coeditors you shared it with will be able to recover it again.

DeleteCancel

Atomic Theory

A Brief History History of the Atom
by

Eric Raine

on 5 October 2014

Comments (0)

Please log in to add your comment.

Report abuse

Transcript of Atomic Theory

Atomic Theory
Democritus
465 BC
Aristotle
350 BC
Matter could not be divided into smaller
& 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.”
Aristotle & Plato
Democritus
465 BC
Aristotle
350 BC
John Dalton
1802

He deduced that all elements are composed of atoms.
Atoms are indivisible
& indestructible particles.
Atoms of the same element
are exactly alike.
Atoms of different elements
are different.
Compounds are formed by
joining of atoms of two or more elements.
But he could never find them. :(
A particle smaller than an atom had to exist.
JJ Thompson
1897
Thomson called the negatively
charged “corpuscles,” today known as electrons.
Since the gas was known to be neutral,
having no charge, he reasoned that
there must be positively charged particles in the atom.
Thompson concluded that the negative
charges came from within the atom.
The atom was divisible!
Ernest Rutherford
1911
Rutherford’s experiment involved firing
a stream of tiny positively charged particles
at a thin sheet of gold foil (2000 atoms thick)

This could only mean that the
gold atoms in the sheet were
mostly open space. Atoms were
not a pudding filled with a
positively charged material.

Rutherford concluded that an atom
had a small, dense, positively charged
center that repelled his positively
charged “bullets.”

He called the center
of the atom the “nucleus”
Rutherford reasoned that all of an atom’s positively charged particles were contained in the nucleus. The negatively charged particles were scattered outside the nucleus around the atom’s edge.
Niels Bohr
1913
He placed each electron
in a specific energy level.

Erwin Schrodinger
1930
Louis de Broglie
1927
According to the theory of wave mechanics, electrons do not move about an atom in a definite path, like the planets around the sun.
In fact, it is impossible to determine the exact location of an electron. The probable location of an electron is based on how much energy the electron has.
Werner Heisenberg
1927
A space in which electrons are likely to be found.

Electrons whirl about the nucleus billions of times in one second

They are not moving around in random patterns.

Location of electrons depends upon how much energy the electron has.

Depending on their energy they are locked into a certain area in the cloud.

Electrons with the lowest energy are found in the energy level closest to the nucleus

Electrons with the highest energy are found in the outermost energy levels, farther from the nucleus.

Full transcript