Cliff Notes I. Reading the Elements A. Periodic table contains every element known to man, even those that were made by man B. element: any material made up of one type of atom C. Each element is represented on the periodic table in an atomic symbol 1. atomic symbol: the symbol representing each element a. if atomic symbols have two letters, the second one is always lower case -Examples: find the atomic symbols for Calcium, Nickel, Chlorine, and Gold II. Atomic Numbers and Mass Numbers A. atomic number: number of protons, defines which element the atom is -Examples: atomic number of Calcium? 20 atomic number of Nickel? Chlorine? Gold? B. atomic mass number: number of protons + neutrons C. To find the number of neutrons in an atom # neutrons = atomic mass # - atomic # 1. round atomic mass # to the nearest whole number -Examples: # of neutrons in Calcium = 40 - 20 = 20 neutrons # of neutrons in Nickel, Chlorine, Gold? |