1. Introduction to the Periodic Table of Elements
Seventh Grade Science
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2. Reading the Periodic Table
Each square gives information about the atoms of the element
Atomic Number (# of protons)
Chemical Symbol
Element Name
Average Atomic Mass

3. Arrangement of Periodic Table
Elements are arranged in vertical columns , called groups or families, to show similarities in their chemical and physical properties
Groups are labeled with a number at the top of their column
Each horizontal row is called a period
Properties of elements change in a predictable way from one end of the period to the other

4. Quiz Quickie
What information is contained on each square of the periodic table?
What do groups on the periodic table show?
How do the properties of elements change as you move from left to right on the periodic table?

5. Periods of the Periodic Table
Periods are horizontal rows that move from left to right on the Periodic Table
As you read from left to right, one proton and one electron are added from one element to the next element
Atomic size increases as you move across the table
Elements on the left side and right side of the table are the least dense
Elements in the middle of the table are the most dense
Osmium (Os) has the highest known density, located in the center of the table

6. Groups of the Periodic Table
Elements on the periodic table are arranged into families, also known as groups, based on their chemical properties.
Each family has a specific name to differentiate it from the other families in the periodic table.
Read from top to bottom
Elements in each family
or group react
differently with
other elements.

7. Quiz Time! How are families or groups arranged on the periodic table?
What happens to the atomic size as you move from left to right across the periodic table?

8. ALKALI METALS Group 1 Hydrogen is not a member, it is a nonmetal
1 electron in the outer shell
Soft and silvery metals
Very reactive, especially with water
Conduct electricity
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9. ALKALINE EARTH METALS Group 2 2 electrons in the outer shell
White and malleable
Reactive, but less than Alkali Metals
Conduct electricity

10. TRANSITION METALS Groups 3 through 12
Good conductors of heat and electricity
Some are used for jewelry
The transition metals are able to put up to 32 electrons in their second to last shell
Can bond with many elements in a variety of shapes

11. Check for Understanding
What are some characteristic properties of elements in the Alkali Metals group or family?
How do the Alkaline Earth Metals differ from the Alkali Metals?
What characteristic do the Alkali, Alkaline Earth and Transition Metals have in common?

12. Metalloids
Metalloids are shown on either side of the zigzag line of the table
Usually depicted as purple in color
Have properties of both metals and nonmetals
Silicon (Si) is the most common metalloid
Make up semiconductors found in electronic devices

13. BORON FAMILY Group 13 3 electrons in the outer shell Most are metals
Boron is a metalloid

14. CARBON FAMILY Group 14 4 electrons in the outer shell
Contains metals, metalloids, and a nonmetal Carbon (C)

15. NITROGEN FAMILY Group 15 5 electrons in the outer shell
Can share electrons to form compounds
Contains metals, metalloids, and nonmetals

16. OXYGEN FAMILY Group 16 6 electrons in the outer shell
Contains metals, metalloids, and nonmetals
Reactive

17. Quiz Quickie!
How does the number of electrons affect the element’s reactivity?
What do the Boron, Carbon, Nitrogen, and Oxygen families have in common?
What is a metalloid and where are they located?

18. Halogens Group 17 7 electrons in the outer shell
All are nonmetals, except Astatine (At)
Very reactive
Often bonded with Group 1 elements

19. Noble Gases Group 18 Exist as gases Nonmetals
8 electrons in the outer shell = Full
Helium (He) has only 2 electrons in the outer shell = Full
Not reactive with other elements

20. Rare Earth Metals Also known as Lanthanide and Actinide Series
Some are radioactive
Silver, silvery-white, or gray metals.
Conduct electricity

21. Checking for Understanding
Why are the Noble Gases considered to be unreactive?
What is it about the Halogen family that makes the elements within that family so reactive?
Where are the Rare Earth Metals located with regard to the periodic table?