-
400 BCE
Democritus (Ancient Greece)
400 b.C.
Early model of the atoms: "All matter is made up small indestructible units he called atoms." -
John Dalton (England)
1803 a.D.
Four postulates about matter:
1. "All matter is made up of tiny particles called atoms."
2. "All atoms of a given element are the same and different from atoms of other elements."
3. "Atoms of two or more different elements combine to form compounds."
4. "Matter cannot be created nor destroyed neither anywhere nor on chemical reactions." -
J.J. Thomson (England)
1897 a.D.
The negative electrons represented the raisins in the pudding and the dough contained the positive charge. Thomson's model of the atom did explain some of the electrical properties of the atom due to the electrons. -
Ernest Rutherford (Britain)
1911 a.D.
He described that the atom is composed by several tiny particles, beign the first look at the atomic structure beyond the positive and negative charged particles. -
Neils Bohr (Denmark)
1913 a.D.
The energy distribution on the atoms is specific and exactly measured, even on their changes of energy levels. -
Erwin Schrödinger (Austria)
1926 a.D.
He developed a model that intrepretted the enegy levels' orbitals as clouds, and that those clouds where the places where the particles are more likely to be found.
