The development of the Periodic table

By Lizeh

  • Dobereiner proposes the law of Triads

  • 62 elements have been discovered

    By 1860, 62 elements have been discovered. Scientists start to discuss diffrent ways of arranging them.

  • John Newlands comes up with the Law of Octives

    John Newlands tried arranging the elements in order of similar properties. He noticed that every elements properties would corrospond with the elements 8 places away from it.

  • Dmitri Mendeleev finds a way of ordering all the known elements

    He organised the elements according to atomic mass in accending order, with the similar elements grouped vertically

  • Lord Raleigh discoveres Argon

    He eported it waa gas at roomtemprture and was very unreactive. It didn't ft ito any groupin the periodic table

  • William Ramsy propses that Argon isput in a new group with Helium

    He called his group group 0. He also accurately predicted the properties and existance of Neon.

  • Henry Moseley changes how the perodic table is ordered

    He orders it according to length or wavelngth, not atomic mass. This clears up alot of irreguaritys within the table