BORNEMISZA PÉTER GIMNÁZIUM, Általános Iskola, Alapfokú Művészeti Iskola és Sportiskola
Tanórán kívül
Development of the atomic model
Key stages of development from Democritus to Heisenberg
Democritus 460 BC - 370 BC

There exists a smallest piece of matter whichcan not be dividedany further
These pieces are called atoms.

Aristotle: No matter how small a matter is it can be dividedinto smaller pieces.
John Dalton 1803

All matters is made of tiny particles called atoms
Atoms are indivisible
Atoms of different elements differ in some way

The compounds contain the same mass ratio of one element to another
Dmitri Mendeleev 1869

Arranged elements in a table so that elemets with similar properties were
in the samecolumn

Elements repeat properties in groups of 8

William Conrad Roentgen 1895

Discovered the x-rays while using cathode-ray tube.
J.J. Thomson 1897

Worked with cathode rays tube

Credited with the discovery of the electron

Plum pudding atomic model
Ernest Rutherford 1899

Studied radioactivity. Alpha, beta , gamma radiation

gold foil experiment, deflection of alpha particle
discovery of nucleus

Simulation of Rutherford's scattering experiment

Niels Bohr

1913 proposed improvemens to Rutherford model
planetary model
fixed orbits, or energy levels for the electron traveling around the nucleus
Werner Heisenberg

Heisenberg Uncertainty principle,

effectively destroys the idea of electrons traveling around in neat orbits

Try with this simulation the different atomic models.

More physics webpages
An excellent video of the discovery of atomic structure
The second part is about cosmic rays, atomic zoo, quarks and particle accelerator
Publikálta: Csaba Zsolt
© 2010 Bornemisza Péter Gimnázium