In 1669 German merchant and amateur alchemist Hennig Brand attempted to created a Philosopher’s Stone; an object thatsupposedly could turn metals into pure gold. He heated residues from boiled urine, and a liquid dropped out and burst into flames. This was the first discovery of phosphorus.
In 1680 Robert Boyle alsodiscovered phosphorus, and it became public.
In 1809 at least 47 elements were discovered, and scientists began to see patterns in the characteristics.
In 1863 English chemist John Newlands dividedthe than discovered 56 elements into 11 groups, based on characteristics.
In 1869 Russian chemist Dimitri Mendeleev started the development of the periodic table, arranging chemical elements by atomicmass. He predicted the discovery of other elements, and left spaces open in his periodic table for them.
In 1886 French physicist Antoine Bequerel first discovered radioactivity. Thomson studentfrom New Zealand Ernest Rutherford named three types of radiation; alpha, beta and gamma rays. Marie and Pierre Curie started working on the radiation of uranium and thorium, and subsequently discoveredradium and polonium. They discovered that beta particles were negatively charged.
In 1894 Sir William Ramsay and Lord Rayleigh discovered the noble gases, which were added to the periodic table asgroup 0.
In 1897 English physicist J. J. Thomson first discovered electrons; small negatively charged particles in an atom. John Townsend and Robert Millikan determined their exact charge and mass.
In1900 Bequerel discovered that electrons and beta particles as identified by the Curies are the same thing.
In 1903 Rutherford announced that radioactivity is caused by the breakdown of atoms.
In1911 Rutherford and German physicist Hans Geiger discovered that electrons orbit the nucleus of an atom.
In 1913 Bohr discovered that electrons move around a nucleus in discrete energy called...