www.middleschoolscience.com 2008

All images are from www.Chem4kids.com

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 ? ?

Periods •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.

Groups

•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.

Group 1 = 1 electron

Group 2 = 2 electrons

Group 8 = 8 electrons

Except for He, it has 2 electrons

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

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1

2

3 4 5 6 7 8 9 10 11 12

13 14 15 16 17

18

Hint: Your Family tree is vertical.

Transition Metals•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.

Determine the number of shells and the

number of valence electrons for:

2nd Period = 2 shells

4th Group = 4 valence electrons

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Determine the number of shells and the

number of valence electrons for:

3rd Period = 3 shells1st Group = 1 valence electron

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Write your answers on your handout.

Name the element.

Number of shells ?

Valence electrons ?

Write your answers on your handout.

8th Group = 8 valence electrons

2nd Period = 2 shells

NeonName the element.

Number of shells ?

Valence electrons ?

Write your answers on your handout.

Name the element.

Number of shells ?

Valence electrons ?

Write your answers on your handout.

1st Group = 1 valence electron

1st Period = 1 shell

HydrogenName the element.

Number of shells ?

Valence electrons ?

Write your answers on your handout.

Name the element.

Number of shells ?

Valence electrons ?

Write your answers on your handout.

2nd Group = 2 valence electrons

2nd Period = 2 shells

BerylliumName the element.

Number of shells ?

Valence electrons ?

Write your answers on your handout.

Name the element.

Number of shells ?

Valence electrons ?

Write your answers on your handout.

6th Group = 6 valence electrons

3rd Period = 3 shells

SulfurName the element.

Number of shells ?

Valence electrons ?

Write your answers on your handout.

Name the element.

Number of shells ?

Valence electrons ?

Write your answers on your handout.

1st Group = 1 valence electron

4th Period = 4 shells

PotassiumName the element.

Number of shells ?

Valence electrons ?

Write your answers on your handout.

Name the element.

Number of shells ?

Valence electrons ?

Write your answers on your handout.

8th Group = 2 valence electrons

1st Period = 1 shell

HeliumName the element.

Number of shells ?

Valence electrons ?

• 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!