Chemistry

1. www.middleschoolscience.com 2008
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2. Period
s •Each row is called a “period”
•The elements in each period have
the same number of shells
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3. Groups
Group 8 = 8 electrons
•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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4. 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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5. 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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6. Determine the number of shells and
the number of valence electrons for:
3rd Period = 3 shells
1st Group =
1 valence
electron
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7. Write your answers on your
handout.
Name the element.
Number of shells ?
Valence electrons ?

8. Write your answers on your
handout.
2nd Period = 2 shells
8th Group = 8 valence
electrons
Name the element. Neon
Number of shells ?
Valence electrons ?

9. Write your answers on your
handout.
Name the element.
Number of shells ?
Valence electrons ?

10. Write your answers on your
handout.
1st Period = 1 shell
1st Group = 1 valence
electron
Name the element. Hydrogen
Number of shells ?
Valence electrons ?

11. Write your answers on your
handout.
Name the element.
Number of shells ?
Valence electrons ?

12. Write your answers on your
handout.
2nd Period = 2 shells
2nd Group = 2 valence
electrons
Name the element. Beryllium
Number of shells ?
Valence electrons ?

13. Write your answers on your
handout.
Name the element.
Number of shells ?
Valence electrons ?

14. Write your answers on your
handout.
3rd Period = 3 shells
6th Group = 6 valence
electrons
Name the element. Sulfur
Number of shells ?
Valence electrons ?

15. Write your answers on your
handout.
Name the element.
Number of shells ?
Valence electrons ?

16. Write your answers on your
handout.
4th Period = 4 shells
1st Group = 1 valence
electron
Name the element. Potassium
Number of shells ?
Valence electrons ?

17. Write your answers on your
handout.
Name the element.
Number of shells ?
Valence electrons ?

18. Write your answers on your
handout.
1st Period = 1 shell
8th Group = 2 valence
electrons
Name the element. Helium
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.

19. End of Study Guide