Development of Periodic Table

Who among the following made the first observation on Platinum as a catalyst and discovered similar triads of elements that led to the development of the periodic table of elements?

When Mendeleev developed his periodic table, chemists knew nothing about the internal structure of atom. His classification was based on their atomic wetghts. Several anomalies persisted in the table with regard to the correct order of atomic weights of (i) K adn Ar (ii) Co and Ni (iii) Te and I

Long form OF Periodic Table (Complete Table OF 118 Elements and Trick to Remember Complete Periodic Table)

Who developed the long form of periodic table?