Slides in this set
Jöns Jacob Berzelius
1779 - 1848
· Berzellius discovered several elements
including cerium, lithium, vanadium and
· He published a table of atomic weights in
· He determined the composition by mass for
· He also introduced letter based symbols for
Johann Wolfgang Dobereiner
1780 - 1849
· In 1829 Dobereiner stated that: "Nature contains triads of
elements where the middles element has properties that are
an average of the other two members of the triad when
ordered by the atomic weight"
· The triads are now recognised as consecutive members of
groups in the periodic table, for example lithium, sodium and
Alexandre-Emile Beguyer de Chancourtois
1820 - 1886
· He devised an early form of the periodic table
· He arranged elements on a spiral in a cylinder
and ordered them by increasing atomic mass.
· Elements with similar properties were aligned
1837 - 1898
· Newlands was the first person to arrange the
elements in the periodic table by their relative
· He arranged 56 elements in order of increasing
atomic mass in groups of 8.
· He pointed out that each element was similar to
the element 8 places from it in the list.
· His work was rejected because he left no gaps for
undiscovered elements and some elements had
similar properties as he did not distinguish
between metals and non-metals.…read more