Miami Beach Senior High School

• CHEM 101

• Module 3 1.Explain how scientific observations led to the development of the periodic table. Dmitri Mendeleev- first periodic table, organized 63 known elements according to properties, organized into rows and columns and wrote name, mass, chemical properties on each Henry Gwyn Jefferys- worke with Earnest Rutherford, experimented with 38 metals,he found in Mendeleev's periodic table ,led to modern definition of atomic number and the recognition the atomic number was to the periodic table 2.Describe the organization of the modern periodic table. A modern periodic table arranges the elements in increasing order of their atomic numbers and groups atom