PERIODIC TABLE
Home
Alkali Metals
Alkaline Earth Metals
Transition Metals
Nonmetals
Metalloids
Halogens
Noble Gases
Ionic Bonding
Mendeleev created the first periodic table in 1869. It is organized by atomic number and valence electrons increase from left to right.The periodic table is organized in groups and periods. There are 18 groups, 7 periods, and 118 elements.