History of the Atom

Timeline created by warbym
  • 355

    Aristotle

    Born 384, in Stagira, Chalcidice. Plato was Aristotle’s teacher and together with Socrates, Plato’s teacher, Aristotle composed of his theory with his four main elements;Earth, Fire, Water and Air and their properties; cold and dry, hot and dry, cold and wet and cold and dry.Aristotle is now one of the important founding figures. All of Aristotle’s philosophy continues to be the main focus of academic study today.
  • 430

    Democritius

    Democritius was a ancient Greek philosopher born in 400BC, who came up with the theory that everything is made up of atoms. He also discovered "Atoms are physically, but not geometrically, indivisible; between atoms lies empty space; atoms are indestructible; have always been, and always will be, in motion; there are an infinite number of atoms and kinds of atoms, which differ in shape, and size". The word atom is devised from the Greek word Atomos, meaning indivisible.
  • Antoine Lavoisier

    Born August 26, 1743 in Paris, France. Lavoisier married MarieAnne Pierrette Paulze in 1771. She translated English documents, one being Richard Kirwan’s ‘Essay on Phlogiston’ and also Joseph Priestley’s work. MarieAnne also sketched and carved engravings of the laboratory instruments used by Lavoisier and his colleagues. In 1772, Antoine worked on processes like combustion / oxidation of metals. Lavoisier’s approach helped chemists realise the important processes to apply the scientific method.
  • John Dalton

    John Dalton
    In 1808, John Dalton published his book, 'A New System of Chemical Philosophy'. His two quotes 'Atoms cannot be subdivided, created, or destroyed into smaller particles when they are combined, separated, or rearranged in chemical reactions' and 'All atoms of a given element are identical in their physical and chemical properties' gave other scientists another perspective on the atom.
  • Ernest Rutherford

    Rutherford was born in 1871. Whilst Rutherford was experimenting radioactivity he discovered two types of radiation emitted by thorium and uranium. He named his findings alpha and beta.Rutherford discovered the nucleus of an atom is dense and has a positive charge.
  • JJ Thomson

    JJ Thomson was born in 1856, Cheetham Hill near Manchester, England. Thomson discovered the electron and the smaller particles inside of the atom. JJ Thomson, an English physicist who discovered the electron and isotopes. In 1911, Thomson researched the nature of positive rays. This significantly helped the discovery of isotopes.
  • Niels Bohr

    Bohr was born in 1885, Copenhagen, Denmark. Bohr enrolled as an undergraduate at Copenhagen University in 1903. He majored in Physics and his teacher was Professor Christian Christiansen who was the university’s only professor. Bohr developed model of the atom with the nucleus in the centre and electrons orbiting around it which he named the Bohr model. He also compared it to planets orbiting the Sun. Bohr also discovered that an electron could drop from a high energy orbit to low energy orbit.
  • James Chadwick

    Chadwick was born October 20, 1981 in Manchester. Ernest Rutherford was the head of the physics department, instructed James to compare the amount of radioactive energy of two different sources. Chadwick followed a line of research the led to the discovery of the neutron in 1932. Chadwick’s early research included beta particles’ energy range and their development. This work gave Wolfgang Pauli help to suggest the existence of neutrino.