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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
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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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 ?
Write your answers on your handout.
Ne
8th Group = 8 valence electrons
2nd Period = 2 shellsNeonName the element.
Number of shells ?Valence electrons ?
Write your answers on your handout.
HName the element. Number of shells ?Valence electrons ?
Write your answers on your handout.
H
1st Group = 1 valence electron
1st Period = 1 shellHydrogenName the element.
Number of shells ?Valence electrons ?
Write your answers on your handout.
BeName the element. Number of shells ?Valence electrons ?
Write your answers on your handout.
Be
2nd Group = 2 valence electrons
2nd Period = 2 shellsBerylliumName the element.
Number of shells ?Valence electrons ?
Write your answers on your handout.
SName the element. Number of shells ?Valence electrons ?
Write your answers on your handout.
S
6th Group = 6 valence electrons
3rd Period = 3 shellsSulfurName the element.
Number of shells ?Valence electrons ?
Write your answers on your handout.
KName the element. Number of shells ?Valence electrons ?
Write your answers on your handout.
K
1st Group = 1 valence electron
4th Period = 4 shellsPotassiumName the element.
Number of shells ?Valence electrons ?
Write your answers on your handout.
HeName the element. Number of shells ?Valence electrons ?
Write your answers on your handout.
He
8th Group = 2 valence electrons
1st Period = 1 shellHeliumName the element.
Number of shells ?Valence electrons ?
• 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
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
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”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
On your worksheet, try these elements on your own:
a) Hb) Pc) Cad) Are) Clf) Al
H
Lewis Structures
On your worksheet, try these elements on your own:
a) Hb) Pc) Cad) Are) Clf) Al
P
Lewis Structures
On your worksheet, try these elements on your own:
a) Hb) Pc) Cad) Are) Clf) Al
Ca
Lewis Structures
On your worksheet, try these elements on your own:
a) Hb) Pc) Cad) Are) Clf) Al
Ar
Lewis Structures
On your worksheet, try these elements on your own:
a) Hb) Pc) Cad) Are) Clf) Al
Cl
Lewis Structures
On your worksheet, try these elements on your own:
a) Hb) Pc) Cad) Are) Clf) Al
Al
End of Study Guide.
Complete the Lewis Structure Worksheet
You should know how to draw Lewis Structures for the first 20 elements.
