-
400 BCE
Democritus
the first discovery of the atom -
John Dalton
Found that each element consisted of its own brand of indivisible atom -
JJ Thompson
Discovered that atoms were made up of smaller components, which he called ‘corpuscles’ (that later became known as ‘electrons’) -
Ernest Rutherford
Found that the atom is mostly empty space, with nearly all of its mass concentrated in a central tiny nucleus -
Niels Bohr
Produced a model of the atom in which the electron was able to occupy only certain orbits around the nucleus. -
James Chadwick
the discovery of a neutron