Periodic Table

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?