-
Democritus theorized that everything in the world was made upon tiny particles in which he called atomos(atoms), but his ideas where opposed by the more popular philosophers.
-
Dalton showed that common substances always broke down into the same elements, he concluded that various compounds where combinations of atoms of different elements that can neither be created or destroyed.
-
A century later Thomson's the electron, and he made the chocolate chip cookie atom model. He showed atoms of uniformly packed spheres of positive mater, build with negatively charged electrons.
-
Rutherford can also be known as the father of the nucleus age, He shot positively charged alpha particles at a sheet of gold foil. Rutherford concluded that atoms consisted largely of empty space with just a few electrons while most of the mass was concentrated in the center which he turned the nucleus, alpha particles passed through the gap but bounced back on the fully charged nucleus.
-
He stimulated that electrons orbit the nucleus at fixed energies and distances, able to jump from one level to another but not exist in the space between.
-
He showed, through math, that waves can be used to describe electrons in atoms. According to Schrodinger, electrons stuck in their orbits would set up "standing waves".
-
He showed that it was impossible to determine both the exact position and speed of electrons as they moved around an atom.
-
James Chadwick proved the existence of neutrons. Chadwick interpreted that radiation as being composed of particles of mass approximately equal to that of the proton but without electrical charge neutrons. Finally his model is the one that we use today.
