Periodic Table Patterns

If you know the patterns, you can use it to find information quickly about the elements

The two patterns we are going to review are the periods and the group numbers

periods are the name for the rows that go across the table

there are 7 rows on the periodic table

the pattern is the elements in a period have the same number of energy levels

as elements get bigger with more electrons, the elements need more space for their electrons.

the bigger the number of electrons, the more energy levels it needs

so as you go down the periodic table, the elements have more energy levels

the maximum number of energy levels is 7

groups go up and down on the periodic table

there are 18 groups on the periodic table

BUT only groups 1 and 2 and 13-18 follow any sort of pattern.

the pattern is the group number can help you quickly figure out the number of valence electrons

valence electrons are the electrons on LAST energy level

valence electrons are the ones responsible for bonding- so VERY important!