Development of the periodic table

By Obsessed_grunt

  • Alexandre-Emile Béguyer de Chancourtois

    French geologist Alexandre-Emile Béguyer de Chancourtois listed the elements on paper tape and wound them, spiral like, around a cylinder. Certain ‘threes’ of elements with similar properties came together down the cylinder. He called his model the ‘telluric screw’.

  • John Newlands

    English chemist John Newlands noticed that, if the elements were arranged in order of atomic weight, there was a periodic similarity every 8 elements. He proposed his ‘law of octaves’ on this.

  • Lothar Meyer

    Lothar Meyer complied a periodic table of 56 elements based on a regular repeating pattern of physical properties such as molar volume. Once again, the elements were arranged in order of increasing atomic weights.

  • Dmitri Mendeleev

    Russian chemist Dmitri Mendeleev produced a periodic table based on atomic weights but arranged ‘periodically’. Elements with similar properties appeared under each other. Gaps were left for yet to be discovered elements.

  • William Ramsay

    William Ramsay discovered the noble gases and realised that they represented a new group in the periodic table.

  • Henry Moseley

    Henry Moseley determined the atomic number of each of the known elements. He realised that, if the elements were arranged in order of increasing atomic number rather than atomic weight, they gave a better fit within the ‘periodic table’.

  • Glenn Seaborg

    Glenn Seaborg artificially produced heavy mass elements such as neptunium. These new elements were part of a new block of the periodic table called ‘actinides’.