Atomic theory

Timeline of Atomic Theory

  • John Dalton

    John Dalton
    John Dalton was a English man
    He studied the Atomic theory in 1808
    He made brilliant discoveries like how matter is a indivisible and indestructible atoms with distinct matter and properties
  • Dmitri Mendeleev

    Dmitri Mendeleev
    On 17 February 1869, Russian chemist Dmitri Mendeleev jotted down the symbols for the chemical elements, putting them in order according to their atomic weights and inventing … the periodic table
  • Henri Becquerel

    Henri Becquerel
    Like Thomson's discovery of the electron, the discovery of radioactivity in uranium by French physicist Henri Becquerel in 1896 forced scientists to radically change their ideas about atomic structure
  • J.J Thomson

    J.J Thomson
    J.J Thomson was from Britain and discovered the electron.
    He discovered that all atoms contain tiny negatively charged subatomic particles or electrons
  • Marie Curie

    Marie Curie
    Then Curie discovered an even more radioactive element, radium, and, through observation of radium, made a fundamental discovery: Radiation wasn't dependent on the organisation of atoms at the molecular level; something was happening inside the atom itself.
  • Ernest Rutherford

    Ernest Rutherford
    Ernest Rutherford is a from New Zealand and discovered something massive in atomic theory.
    In 1911, Rutherford described the atom as having a tiny, dense, and positively charged core called the nucleus
  • Frederick Soddy

    Frederick Soddy
    Frederick Soddy was a scientist who made significant contributions to atomic theory. His theory of isotopes explains that different elements can be chemically indistinguishable but have different atomic weights and characteristics.
  • Niels Bohr

    Niels Bohr
    In 1922, 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
  • Erwin Schrödinger

    Erwin Schrödinger
    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
  • James Chadwick

    James Chadwick
    James Chadwick discovered the neutron, a subatomic particle with no charge that adds to the atomic weight in 1930.