Adapted by Mrs. Hunt from Mrs. LaRosa

www.middleschoolscience.com 2008

All images are from www.Chem4kids.com

“God’s Operating System”

OBJECTIVESWhat should you be able to do at the end of class?

•Describe the basic organization of the periodic table of elements.

•Use the periodic table to determine the number of electron shells and valence

electrons of an element.

The Periodic Table of Elements is a way of organizing the elements in relation to each other so it is easy to find elements that have similar properties.

It allows scientists to make predictions and explain events.

What is the Periodic Table of Elements?

Why is that helpful?

Here is a “periodic” table. What is it?

The columns are called “GROUPS” or families.

What is represented by the groups on this periodic table? DAYS

The rows are “PERIODS”. What information is in the horizontal periods? WEEKS

Certain information is missing.

How would you find the missing data?

Group 5

Period 3 ? ?

•Each row is called a “period”

•The elements in each period have the same number of electron shells

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Hint:

A period comes at the end of a sentence--a horizontal line.

•Each column is called a “group” or family.

•Each element in a group has the same number of electrons in its outer orbital, also known as its outer shell.

Except for He, it has 2 electrons

•The electrons in the outer shell are called “valence electrons.”

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12

3 4 5 6 7 8 9 10 11 12

13 14 15 16 17

18

Hint: Your Family tree is vertical.

•Transition Metals have slightly different rules for shells and valence electrons.•This is something you will learn about in High School Chemistry.

•For now, assume they each have two valence electrons.

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Use the periodic table.

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• Helium is the exception in Group 18.

• Since it has just one shell, that shell can only fit 2 electrons instead of 8.

• It is in this group because all the elements have a full outer shell.

Review:

How is the Periodic Table of Elements organized?

How can I tell how many electron shells an element has?

How can I tell how many valence electrons an element has?

Questions of the day…

How are the elements arranged in the Periodic Table of Elements?

Back row:

In rows called periods and columns called groups or families

Third row:The elements in a row or period have the same number of what?

Electron shells

Second row:The elements in a column or family (group) have the same number of what?

Valence electrons (electrons in the outer shell)

First row:Find the element Al (13) and tell how many electron shells and valence electrons it has. Know why.

Aluminum has 3 electron shells and 3 valence electrons.

Tomorrow:

Characteristics of the

Families on the Periodic Table.

118 elements known to man, but God’s word is the original

element establishing them

all!