-
John Dalton gave all the (36) elements a symbol and arranged them in order of atomic mass.
-
At this time 55 elements have been discovered so Johann Dobereiner combined the elements into groups of 3
-
Arranged 60 known elements by there atomic mass in a grd called the law of octaves
-
Used cards to arrange elements by atomic mass, and relation.
-
Discovery of electrons by J.J. Thomson.
-
Used atomic number instead of atomic mass
-
Discovery of electron configuration. This led to a change in the periodic table creating the table as we know it today.
-
Seperated Elements in Metals, Non-metals and 'Earths'