Chemistry Unit 3

The Periodic Table

• The elements are in order of atomic number
• Elements with the same porperties are sorted into groups

John Newlands (1864)

• He only knew of the existence of 63 elements
• He arranged them in order of relative atomic mass
• He found similar properties amongst every eighth element in the seris

Dimitri Mendeleev (1869)

• He left gaps to accomidate new discoveries