Chemistry Atoms

Front 1

Democratis

Back 1

first idea about the atom

Front 2

John Dalton

Back 2

1. All matter is composed of tiny, indvisible partices called atoms
2.Atoms of the same element are identical, and are different from those of any other element
3. Atoms combine in simple, whole number ratios form compounds
4. Atoms may be separated, joined, or rearranged in chemical reactions. They may not be changed to form a new element.

Front 3

J.J. Thomson

Back 3

discovered electrons using cathode rays

Front 4

Ernest Rutherford

Back 4

discovered a small concentrated positive area (nucleus) in the atom as a result of the gold foil experiment
-atom is mostly empty space

Front 5

Neil Bohr

Back 5

studied the atomic sectra of H
-discrete wavelengths of light seen because of specific amounts of E being emitted
-planetary model

Front 6

Quantum Mechanical Model

Back 6

E not in a fixed path rather are restricted to a specific 3 dimensional space(known as cloud or orbital)
95% probability of finding e within a particular cloud

Front 7

James Chadwick

Back 7

more mass in nucleus than could be accounted for by the proton
discovery of neutron particle in nucleus with slightly more mass than a proton but unchanged