Modern Versions of the Perodic Table
The last major changes to the Periodic Table were made during the middle of the last century with much of the work being credited to Glenn Seaborg, who won the Nobel prize for chemistry for his work in this area, something Mendeleyev never achieved for his work on the same subject! His work included the discovery of Plutonium and the entire actinide series, elements 94-102 which using periodic law, he placed above the Lathanide series. He, like Mendeleyev has an element named after him. Seaborgium (Sg) is the 106 element in the periodic table.
Since 1869, numerous table designs have been proposed to demonstrate the periodic law. Here are a couple of examples which have been produced since Mendeleyev's first example in 1869:
Triangular form of the Periodic Table
This periodic table was the work of Emil Zmaczynski and graphically represents the process of constructing electron shells for atoms.
The Physicists Periodic Table
This periodic table was constructed by Timmothy Stowe and depicts periodicity in terms of quantum numbers.
Other forms of the periodic table include a spiral periodic table (Theodor Benfey ) and a 3-D periodic table by Paul Giguere which based primarily on the electronic structure of the atoms.