The Periodic Table. Periods Each row is called a “period” The elements in each period have the...

The Periodic Table

Determining Shells and Valence Electrons

Periods •Each row is called a “period”

1st Period = 1 Shell

2nd Period = 2 Shells

3rd Period = 3 Shells

4th Period = 4 Shells

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

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Groups

•Each column is called a “group”

•Each element in a group has the same number of electrons in their outer orbital, also known as “shells”.

Group 1 = 1 electron

Group 2 = 2 electrons


Except for He, it has 2 electrons

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

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3, 4, 5, 6, 7


Transition Metals

•Transition Metals have slightly different rules for shells and valence electrons.

•This is something you will learn about in High School Chemistry.

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Determine the number of shells and the number of valence electrons for:

Carbon - C2nd Period = 2 shells

4th Group = 4 valence electrons

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Determine the number of shells and the number of valence electrons for:

Sodium - Na3rd Period = 3 shells

1st Group = 1 valence electron

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Write your answers on your handout.

NeName the element. Number of shells ?Valence electrons ?


Ne


2nd Period = 2 shellsNeonName the element.

Number of shells ?Valence electrons ?


HName the element. Number of shells ?Valence electrons ?


H


1st Period = 1 shellHydrogenName the element.



BeName the element. Number of shells ?Valence electrons ?


Be

2nd Group = 2 valence electrons

2nd Period = 2 shellsBerylliumName the element.



SName the element. Number of shells ?Valence electrons ?


S


3rd Period = 3 shellsSulfurName the element.



KName the element. Number of shells ?Valence electrons ?


K


4th Period = 4 shellsPotassiumName the element.



HeName the element. Number of shells ?Valence electrons ?


He


1st Period = 1 shellHeliumName the element.


• Helium is the exception in Group 8.

• 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.

Be sure to have all your answers on the worksheet.

End of Study Guide

The Atom and Periodic Table

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How to Draw Lewis Structures

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Lewis Structures

1) Find your element on the periodic table.2) Determine the number of valence electrons.3) This is how many electrons you will draw.

Lewis Structures

• Find out which group (column) your element is in.

• This will tell you the number of valence electrons your element has.

• You will only draw the valence electrons.

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Groups - Review

•Each column is called a “group”

•Each element in a group has the same number of electrons in their outer orbital, also known as “shells”.

Group 1 = 1 electron



Except for He, it has 2 electrons

•The electrons in the outer shell are called “valence electrons”www.chem4kids.com

3, 4, 5, 6, 7


Lewis Structures

1) Write the element symbol.

2) Carbon is in the 4th group, so it has 4 valence electrons.

3) Starting at the right, draw 4 electrons, or dots, counter-clockwise around the element symbol.

C

Lewis Structures

1) Check your work.2) Using your periodic

table, check that Carbon is in the 4th group.

3) You should have 4 total electrons, or dots, drawn in for Carbon.

C

Lewis Structures

On your worksheet, try these elements on your own:

a) Hb) Pc) Cad) Are) Clf) Al

C

Lewis Structures



H

Lewis Structures



P

Lewis Structures



Ca

Lewis Structures



Ar

Lewis Structures



Cl

Lewis Structures



Al

End of Study Guide.

Complete the Lewis Structure Worksheet

You should know how to draw Lewis Structures for the first 20 elements.

The Periodic Table. Periods Each row is called a “period” The elements in each period have the...

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