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Period: 470 BCE to 380 BCE
Democritus develops the concept of an atom.
He developed the concept of the 'atom', Greek for 'indivisible'. Democritus believed that everything in the universe was made up of atoms, which were microscopic and indestructible. -
Period: 470 BCE to 380 BCE
Democritus develops the concept for atom
He developed the concept of the 'atom', Greek for 'indivisible'. Democritus believed that everything in the universe was made up of atoms, which were microscopic and indestructible. -
Period: 470 BCE to 380 BCE
Democritus develops the concept of an atom.
He developed the concept of the 'atom', Greek for 'indivisible'. Democritus believed that everything in the universe was made up of atoms, which were microscopic and indestructible. -
Daulton
Dalton's atomic theory proposed that all matter was composed of atoms, indivisible and indestructible building blocks. While all atoms of an element were identical, different elements had atoms of differing size and mass. -
Dalton discovered the atomic theory
Dalton's atomic theory proposed that all matter was composed of atoms, indivisible and indestructible building blocks. While all atoms of an element were identical, different elements had atoms of differing size and mass. -
Dalton discovers the atomic theory.
Dalton's atomic theory proposed that all matter was composed of atoms, indivisible and indestructible building blocks. While all atoms of an element were identical, different elements had atoms of differing size and mass. -
J.J. Thomson discovers the electron.
J. J. Thomson, who discovered the electron in 1897, proposed the plum pudding model of the atom in 1904 before the discovery of the atomic nucleus in order to include the electron in the atomic model. -
J.J. Thomson discovers the electron.
J. J. Thomson, who discovered the electron in 1897, proposed the plum pudding model of the atom in 1904 before the discovery of the atomic nucleus in order to include the electron in the atomic model -
Sir Earnest Rutherford discovers the two types of particles in uranium.
He discovered that there are two types of radiation, alpha and beta particles, coming from uranium. He found that the atom consists mostly of empty space, with its mass concentrated in a central positively charged nucleus. -
Earnest Rutherford discovers an atom nucleus.
In 1911, he was the first to discover that atoms have a small charged nucleus surrounded by largely empty space, and are circled by tiny electrons, which became known as the Rutherford model (or planetary model) of the atom. -
Bohr discovers that electrons travel in separate orbits.
Bohr was the first to discover that electrons travel in separate orbits around the nucleus and that the number of electrons in the outer orbit determines the properties of an element. -
Bohr discovers that electrons travel in separate orbits.
Bohr was the first to discover that electrons travel in separate orbits around the nucleus and that the number of electrons in the outer orbit determines the properties of an element. -
Heisenberg contributes to quantum mechanics.
Werner Heisenberg was a German physicist and philosopher who is noted for his crucial contributions to quantum mechanics. He devised a method to formulate quantum mechanics in terms of matrices, for which he was awarded the 1932 Nobel Prize for Physics. -
Heisenberg contributes greatly to quantum mechanics.
Werner Heisenberg was a German physicist and philosopher who is noted for his crucial contributions to quantum mechanics. He devised a method to formulate quantum mechanics in terms of matrices, for which he was awarded the 1932 Nobel Prize for Physics. -
Erwin Schrödinger improves the Bohr model using mathematical equations.
In 1926 Erwin Schrödinger, an Austrian physicist, took the Bohr atom model one step further. Schrödinger used mathematical equations to describe the likelihood of finding an electron in a certain position. -
Erwin Schrödinger improves the Bohr model by using mathematical equations.
Austrian physicist Erwin Schrödinger was a noted theoretical physicist and scholar who came up with a groundbreaking wave equation for electron movements.