1. noble gas envy
ions

2. ChemCatalyst
One atom of Lithium and one atom of Fluorine form a very strong bond. This is because the lithium atom gives up its valence electron to the fluorine atom.
1. What benefit occurs to either atom as a result of the transfer of the electron?
Unit 1 • Investigation V 2

3. Why would atoms want to gain or lose electrons?

4. Stability
This is because they have the maximum number of valence electrons allowed

5. What is the maximum number of valence electrons any atom can have?

6. Except for hydrogen and helium, It is 8

7. What atoms have a full valence shell?

8. Noble gases

9. Noble Gas Configuration and reactivity
All atoms want their valence electron shell filled
This is the most stable electron configuration
Once valence shell is filled, atom stops reacting to or bonding with other atoms.
Since noble gases start out with a filled shell, they do not react with any other substance

10. Why some atoms gain electrons and some lose electrons
Remember, the goal of all atoms is to have a full valence shell
Except for helium, a full shell has ____ electrons
Atoms will gain or lose electrons to fill or empty the shell

11. Actions of atoms
Atoms with 5-7 electrons want to add electrons to fill the outer shell
Atoms with 1-3 electrons want to lose all electrons in that outermost shell
Atoms with 4 electrons and Hydrogen atoms can either gain or lose electrons

12. Ion An atom that gains or loses control of electrons is called an ion
All ions are no longer neutral, because they have a different number of electrons compared to protons

13. Lab Task, part 1 To create several sets of Ion cards for the class
Working in teams of 4 to complete one set (each person completes 7 cards)
Each card indicates the following information on one atom:
Name
Symbol
Atomic number, mass of most common isotope
# Valence electrons (electron config. for honors)
# Core electrons
A Bohr diagram that indicates Number of protons and neutrons and shows the electrons as circles on the rings

14. Division of cards Team member 1: H, Ca, B, Si, As, F, Ne
Team Member 2: Li, Mg, Al, Ge, O, Cl, Ar
Team Member 3: Na, Be, Ga, N, S, Br, He
Team Member 4: K, He, C, P, Se, Kr, Cl

15. Example
Mass of most common isotope: Round the Atomic mass on the periodic table
Core electrons: number of electrons not on the outer ring
Beryllium Be
At#: 4 Mass: 9
Valence: 2 [He] 2s2
Core: 2

16. On Bottom of card
Indicate whether atoms wants to gain or lose electrons to obtain Noble Gas Configuration
Indicate how many electrons will be gained or lost to achieve NGC
On bottom of card write “Ion type:” and leave blank

17. Example, revisited again
Cations are atoms that want to lose electrons
Name : symbol,# electrons lost, + sign
Anions are atoms that want to gain electrons
Name: symbol, # electrons gained, - sign
Beryllium Be
At#: 4 Mass: 9
Valence: 2 [He] 2s2
Core: 2
Wants to lose 2 e-
Ion type: Cation Be2+

18. Complete information at the bottom on all cards

19. Cation An atom that has lost electrons
More protons than electrons results in a positive charge
Na+, Ca 2+, B 3+

20. Anion An atom that has gained electrons
Less protons than electrons results in a negative charge
F-, O2-, P3-

21. Example, revisited for 3rd time
Atoms with 5-7 electrons want to add electrons to fill the outer shell
Atoms with 1-3 electrons want to lose all electrons in that outermost shell
Atoms with 4 electrons and Hydrogen atoms can either gain or lose electrons
Atoms with 8 electrons or Helium do not gain or lose electrons
Beryllium Be
At#: 4 Mass: 9
Valence: 2 [He] 2s2
Core: 2
Wants to lose 2 e-
Ion type:

22. Fill out Ion type, name for all cards

23. Bi Ba Lewis dot structure
Drawn when only valence electrons are important
The center of the structure is the symbol of the element
Dots (which represent valence electrons), are placed on any side of the symbol (including top and bottom)
No more than 2 dots on any side Bi Ba

24. Turn you cards over Draw the Lewis Dot diagram for each card
Make sure symbol and dots fill most of page
Write your name on the bottom of each card

25. Form Groups Teams of 4 Each member will have a different number 1-4
Arrange the cards as the elements appear in the periodic table

26. Questions to be answered by the group
Describe the position occupied all the potential Cations, Anions be located in the cards? In the periodic table?
1a) Turn over the cards so that their Lewis dot diagrams show. Add up the number of dots showing on lithium and fluorine combined. These atoms formed a bond. What must be true for any pair of atoms that forms a bond?
2. Name 10 pairs of elements would like to bond together.
3. Name 5 pairs of elements that would never bond together (may not include noble gases)
4. What element would like to combine with 3 hydrogen atoms? List all possibilities

27. Lab group questions, continued
5) Determine which of the following could be real compounds: NaF, SrXe, MgO, SbRb3 6) To be a real compound what must the sum of all the components valence electrons be? 7) In order to be a compound, there must be at least one Cation and one Anion. For the compounds in question 5 identify which components are Anions or Cations and write their name

28. The Big Question
What ion charges are formed when atoms attain a noble gas electron configuration?
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29. You will be able to:
Predict what would have to happen for potassium to obtain a noble gas configuration.
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30. Activity
Purpose: You will explore the ions that are formed when atoms give up and receive electrons from other atoms.
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31. Notes
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32. Making Sense
Why do you think the noble gas configuration is especially stable?
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33. Notes
A valuable piece of information helps us predict which ions might be encountered in chemistry: Atoms tend to lose or gain electrons to attain the electron configuration of the noble gas nearest to it on the periodic table.
(cont.)
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34. Atoms with a positive charge are called cations.
Ion Names
Atoms with a positive charge are called cations.
Atoms with a negative charge are called anions.
Unit 1 • Investigation V 34

35. Check-In
Write the electron configuration or draw the Lewis Dot Diagram for potassium, K.
What would have to happen for potassium to have a noble gas configuration? Explain.
What would have to happen for an atom of K to become stable?
Is it a cation or anion?
Unit 1 • Investigation V 35

36. Wrap-Up
Noble gases are stable with filled outermost s and p subshells.
Atoms can gain or lose electrons to end up with a noble gas configuration.
When atoms lose electrons, they have a positive charge and are called cations.
When atoms gain electrons, they have a negative charge and are called anions.
Unit 1 • Investigation V 36

37. Where do the electrons go if their released
Where do electrons come from if they are gained?