History of atom timeline

Democritus (460-370) BC

400 BCE

was the first person to propose that atoms existed

Antoine Lavoisier (1772-1794)

Oct 28, 1772

named the elements carbon, hydrogen, and oxygen. Discovered oxygen’s role in combustion and respiration.

John Dalton (1800-1844)

Oct 28, 1800

came up with Dalton’s Law of Partial Pressures

Dmitri Mendeleev (1869)

Oct 28, 1869

He published the original version of the periodic table which was then changed by Moseley.

Eugen Goldstein (1886)

Oct 28, 1886

He was credited with the discovery of protons.

Henry Moseley (1887)

Oct 28, 1887

Discovered that elements are determined by their atomic number, and rearranged the elements on the periodic table

J.J. Thomson (1894-1918)

Oct 28, 1897

discovered the electron and proved the existence of isotopes in stable elements

Max Planck (1900)

Oct 28, 1900

Created the quantum theory of energy.

Ernest Rutherford (1907)

Oct 28, 1907

A nuclear physicist who was the first to split an atom,also he discovered that nearly all the mass of an atom was held in the nucleus, he was named “The Father of the Nuclear age.”

Robert Millikan (1908-1913)

Oct 28, 1908

discovered the charge of an electron and won the nobel prize for it in 1923

Niels Bohr (1912-1962)

Oct 28, 1913

He discovered the form of an atom and created the atomic model. He also came up with the liquid drop theory and formed the early basis of the quantum theory

Werner Heisenberg (1925)

Oct 28, 1925

Noted for his crucial contributions to quantum mechanics. He devised a method to formulate quantum mechanics in terms of matrices

Erwin Schrodinger (1926)

Oct 28, 1926

He took the bohr model one step further by describing the likelihood of finding an electron in a certain position, this is known as the quantum mechanical model of the atom.

James Chadwick (1932)

Oct 28, 1932

discovered the existence of neutrons