PERIODIC TABLE - REVIEW

Group 1A	Known as Alkali Metals Very reactive Never found free in nature React readily with water
Group 2A	Known as Alkaline earth elements All are metals Occur only in compounds React with oxygen in the general formula EO (where O is oxygen and E is Group 2A element)
Group 3A	Metalloids Includes Aluminum (the most abundant metal in the earth) Forms oxygen compounds with a X2O3 formula
Group 4A	Includes metals and nonmetals Go from nonmetals at the top of the column to metals at the bottom All oxygen form compounds with a XO2 formula
Group 5A	All elements form an oxygen or sulfur compound with E2O3 or E2S3 formulas
Group 6A	Includes oxygen, one of the most abundant elements. Generally, oxygen compound formulas within this group are EO2 and EO3
Group 7A	Elements combine violently with alkali metals to form salts Called halogens, which mean "salt forming" Are all highly reactive
Group 8A	Least reactive group All elements are gases Not very abundant on earth Given the name noble gas because they are not very reactive

There are two main classifications in the periodic table, "groups" and "periods."

• ·         Groups are the vertical columns that include elements with similar chemical and                 physical properties.
• ·         Periods are the horizontal rows.
• ·         Going from left to right on the periodic table, you will find metals, then metalloids,             and finally nonmetals.
• ·         The 4th, 5th, and 6th periods are called the transition metals. These elements are          all metals and can be found pure in nature. They are known for their beauty and                 durability. The transition metals include two periods known as the lanthanides and           the actinides, which are located at the very bottom of the periodic table.