1. ___ Mn _____________ 54.9 Fill in the following information: Atomic Number: _______ Element Name: _________ # Protons _____ # Electrons _____ # Neutrons _____ Unit 3: Chemistry. Groups, Periods, and Families. Bell Ringer

2. Unit 3: Chemistry. Groups, Periods, and Families.

3. In the 1860’s, Russian chemist, Dmitri Mendeleev noticed that elements were periodic, meaning they had a regular, repeating pattern. He arranged the elements by atomic number (proton number) Unit 3: Chemistry. Groups, Periods, and Families. Discovering a Pattern

4. Each horizontal row of elements on the periodic table is called a period Unit 3: Chemistry. Groups, Periods, and Families. Periods

5. The elements in each period have the same number of electron shells (electron cloud levels) www.chem4kids.com Unit 3: Chemistry. Groups, Periods, and Families. Periods

6. Unit 3: Chemistry. Groups, Periods, and Families. Periods

7.  Each vertical column on the periodic table is called a group. Unit 3: Chemistry. Groups, Periods, and Families. Groups

8. Each element in a group has the same number of electrons in their outer orbital (shell) The groups are also given family names Unit 3: Chemistry. Groups, Periods, and Families. Groups

9. Except He, it has 2 electrons www.chem4kids.com Unit 3: Chemistry. Groups, Periods, and Families. Groups