Periodic Table #1

Front

Dmitri Mendeleev

Back

Credited with arranging the elements into the first periodic table

Placed elements in the same group that have similar properties

Front

Modern Periodic Table

Back

Elements are arranged by increasing atomic number

Increasing number of protons

Front

Group

Back

Vertical Columns

1-18

Element within the same group have the same number of valence electrons

Front

Period

Back

Horizontal Rows

1-7

Elements within the same period have the same amount of occupied principle energy levels (PELs, electron shells)

Front

Alkali Metals

Back

Group 1

Most Reactive Metals

1 valence electrons, form +1 ions

Front

Alkaline Earth Metals

Back

Group 2

2 valence electrons, form +2 ions

Front

Transition Metals

Back

Groups 3-12

Metals with multiple oxidation states

Form ions that are associated with color in aqueous solutions

Front

Halogens (Halides)

Back

Group 17

Most reactive nonmetals, easily gain electrons

Front

Diatomics

Back

H₂O₂F₂Br₂I₂N₂Cl₂

Front

Noble Gases

Back

Group 18

Chemically non-reactive

Have 8 valence electrons (full valence shell) = stable