-
100
Democritus
Born 460 BC Died 370 BC Famous for the question “Can 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. “ leading to the Democritus theory -
Daltons atomic theory
All matter is made of atoms. Atoms are indivisible and indestructible. -
John Dalton
Born 1766 Died 1844. He proceeded to calculate atomic weights from percentage compositions of compounds; using a special system he called arbitrary system to determine the likely atomic structure of each compound. -
Cathode Ray Tube
is a vacuum tube containing an electron gun -
Gold Foil Experiment
conducted by Rutherford led to the discovery that most of an atom's mass is located in a region now called the nucleus. -
Rutherford Model
is a model of the atom devised by Ernest Rutherford. -
Joseph John Thomas
- Born 1866 Died 1940 discovered the electron in a series of experiments. He used a high-vacuum cathode-ray tube. He also suggested in 1994 that the model of an atom was round with electrons orbiting it
-
Electron Cloud Model
The electron cloud model is an atom model wherein electrons are no longer depicted as particles moving around
