Periodic Table of elements

• ANTOINE LAVOISIER, 1789

  ▪ father of modern

  chemistry

  ▪ publishes a list of 33 elements

  ▪ final stage of chemical

  decomposition
• JOHN DALTON, 1805

  ▪ father of the modern

  atomic theory

  ▪ "A New System of

  Chemical Philosophy,"

  ▪ the atoms of an element

  are identical in mass
• WOLFGANG DOBEREINER, 1829

  ▪ to discover triads

  ▪ relationships among several

  groups of three elements

  ▪ one of the three elements is

  the average of the two others

  in two respects
• Alexandre-Emile Béguyer, 1863

  ▪ arranges the elements in a

  line in order of increasing

  atomic weight
• John Alexander Reina Newlands

  and William Odling

  ▪ working independently in

  England

  ▪ publish two-dimensional

  periodic tables
• John Alexander Reina Newlands

  1869

  ▪ He arranged all elements

  known at that time in the

  order of their atomic masses-

  beginning with lithium.

  ▪ the eighth element has

  similar properties to that of

  the first element

  ▪ the Law of Octaves
• JULIUS LOTHAR MEYER, 1868

  ▪ publishes a number of

  periodic tables that

  represent the discovery of

  a fully mature table

  system

  ▪ successfully

  accommodates most of

  the more than 60 then-

  known elements
• DMITRI MENDELEEV, 1869

  ▪ publishes his first of many

  periodic tables and

  predicts the existence of

  four new elements that he

  provisionally names eka-

  aluminum, eka-silicon,

  eka-boron, and eka-

  manganese.
• WILLIAM RAMSAY, 1893-1898

  ▪ Sir William Ramsay, John

  Strutt or Lord Rayleigh,

  and Morris Travers

  ▪ Discovered Noble Gases
• HENRY MOSELEY, 1913-1914

  ▪ accurately ordered

  according to an ordinal

  number, subsequently

  named “atomic number,”