-
460
Democritus (460-370 BC)
He got credit for naming particles atoms
He believed that atoms were infinite in number, alaways moving and could combine with other atoms -
John Dalton (1766-1844)
He said atoms are industructable and are indivisible
He said you cant create nor destroy atoms -
J.J. Thomsom (1856- 1940)
He found out there were negative and positive particles in an atom
He called the negative particles electrons -
Max Planc (1858-1947)
Max Planck, a professor of theoretical physics in Berlin showed that when you vibrate atoms strong enough, such as when you heat an object until it glows, you can measure the energy only in discrete units. He called these energy packets, quanta. -
Ernest rutherford
He found out that Thomson's model was incorret
HE said the positive charge was located in the nucleus and that most of the atom was empty space -
Neils Bohr (1885- 1962)
He refined rutherford's model
He proposed that eletrons orbit the nucleus and could only move in fixed orbits of sprcific energies -
James Chadwick (1891- 1974)
Chadwick's discovery of the neutron comfirmed a prediction by rutherford
He said protons are 2000 the mass of an electron -
J.J. Thomsom
He won the Nobel Prize in Physics -
Rutherford
He won the Nobel Prize in Chemistry -
Bohr
He won the nobel Prize in Physics
