atomic theory

AtomicTheory

Dalton (1803)•Came up with the first atomic theory: 1.All matter is made of atoms2.Atoms cant be created or destroyed3.Atoms of the same element are identical, different elements are different4.Compounds formed from elements in specific ratios•Created the Billiard Ball Model

Thomson (1896)•Created the Plum Pudding Model (left)•Created the Cathode Ray Tube Experiment (above)•Concluded that there were negative charges in the Cathode Ray•Also discovered electrons and that shared atoms can be broken downThis discovery was important becausediscovered electrons which scientists would not have even known about, somuch wrong information could havecame about.

Rutherford (1909)•Gold Foil Experiment: alpha particles beam was shot at a piece of gold foil paper. Most of the particles went right through it, about .1% was deflected.•Created the Nuclear Model:

Bohr (1911)•Discovery: electrons in atoms exist in specific energy levels around the nucleus.•Bohr Model of the atom – electrons orbit the nucleus in different energy levels at certain distances from the nucleusThis discovery was important because he showed all the electron clouds which helped other scientists build on more information.

THOMSON

DALTON

BOHR RUTHERFORD