THE PERIODIC TABLE AND PERIODIC LAW (CHAPTER 6) A little history… Dmitri Mendeleev Drew a parallel between an element’s properties and their weights Henry Moseley Rearranged the table according to atomic number.

THE MODERN TABLE Representative elements Transition elements

3 GENERAL CLASSIFICATIONS And Metalloids!!!

ANOTHER WAY TO CLASSIFY Halogens Noble gases By “valence” number Number of outer electrons “8” is the goal, then it is stable (octet rule) S-, p-, d-, and f-block

PERIODIC TRENDS atomic radius decreases increases

ANOTHER TREND… electronegativity (the ability to attract electrons) increases decreases

AND YET ANOTHER… Ionization energy Energy to remove an electron Generally increases Generally decreases