The Periodic Table of Elements The Periodic Table is arranged by atomic number and atomic mass Columns = groups Rows = periods Group 1 Alkalis = highly reactive when exposed to water it will explode ( in batteries) Group 17= Halogens (in light bulbs) Group 18 = Noble Gases do not react or bond with others

Elements On the Periodic Table Represented by a chemical symbol When broken down you only get smaller pieces of the element Pure substance, can not be chemically separated,

Atomic Structure The subatomic particles are: Protons, Neutrons and Electrons Protons = Positive charge (+), the number of protons gives you the element name Neutrons = no charge (neutral) Electrons = Negative charge (-) Nucleus = Protons and neutrons live here Atomic Number = number of the Protons Atomic Mass = number of Protons plus (+) number of Neutrons