Name ______period ______Date ______

Ionic Bonding POGIL

Goals: 1) Students will use the periodic table to determine the number of electrons in the valance shell of an atom using their knowledge of electron configurations 2) Students will apply the octet rule in determining how various elements combine chemically using the octet rule 3) Students will Draw the corresponding Lewis diagram for a compound

Part I information: Determining valence electrons Any atom’s electron configuration always has its “s” & “p” orbitals in the outermost energy level. This is called the valence shell. The “d” & “f” orbitals always fill in on lower energy levels. As a result, there can not be more than 8 electrons in the valence shell. The only exception is the first energy level. It only needs 2 electrons because it only has the “s” orbital, there is no “p” orbital in the first energy level. When an atom obtains a full compliment of 8 valence electrons in its valence shell it is the most stable that it can be. This tendency for matter to be stable, a quest to have 8 electrons in the outermost energy level, drives atoms to combine chemically.

Critical thinking questions part 1 : 1) How do you determine how many “s” electrons are in the valence shell? 2) How do you determine how many “p” electrons are in the valence shell? 3) How would you determine how many valence electrons an element had? 4) How does the group that an element is in affect the number of valence electrons?

Exercises: Determine how many valence electrons each element has 1) He 2) Ar 3) Si 4) Ge 5) Ca 6) Sr 7) Fe 8) Ru 9) Nd 10) U

Part II Information: All elements that have 1 or 2 electrons in their valence shell are considered metals. This would include any element that was found in group 1 through group 12. (excluding Hydrogen group 1, and including Aluminum group 13) These elements are known as “electron givers”. In order to reach stability they surrender 1 or 2 electrons.

Image found at: web.buddyproject.org/web017/web017/metals.html By surrendering electrons, the inner energy level that has eight electrons now becomes its valence shell

Sodium atom with one valence electron

Sodium atom when it loses an electron Notice that when the one electron is given away, it has the electron configuration of Neon a Nobel gas.

The elements to the right of the diagonal line on the periodic table with the exception of group 18 are non-metals. These elements are known as electron takers in ionic bonding.

Critical thinking questions part II 1) Elements in group one would most likely give an electron to elements in what

other group? ______Explain why: ______

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2) Elements in group 16 would most likely take electrons from elements in what

other group? ______Explain why: ______

______3) A single atom from group 16 would have to take electrons from how many atoms

from group1? ______Explain why: ______

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4) Come up with a rule for the element groups and how they combine chemically?

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Exercises 1) How many sodium atoms would be needed to bond with Chlorine? ______

2) How many sodium atoms would be needed to bond with Oxygen? ______

3) How many Calcium atoms would be needed to bond with Sulfur? ______

4) How many Calcium atoms would be needed to bond with Chlorine? ______

Part III Lewis Diagrams Lewis diagrams are a way to represent the valence electrons for an atom by placing dots around the chemical symbol to represent electrons. For instance: Chlorine has 7 valance electrons and Sodium has one valence electron. (see diagram below)

From the diagram it is easy to see how the electron from sodium fits right in with the Chlorine atom. To bond Sodium with Oxygen you would need 2 Sodium atoms for every one Oxygen atom. (see diagram below) This type of bonding is called ionic bonding. When an atom gives away an electron it becomes positively charged, and when an atom takes an electron it becomes negatively charged. When the two atoms have opposite charges they are attracted to each other. This electrical attraction between two ions forms a chemical bond.

Critical Thinking questions part III: 1) What groups would bond in a one to one ratio? Explain why: ______

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2) What groups would bond in a two to one ratio? Explain why: ______

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3) What groups would bond in a three to one ratio? Explain why: ______

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Exercises: Draw the Lewis diagram for the element

1) F

2) Li

3) Mg

4) Cl

5) S

6) K

Draw the Lewis diagram when two atoms bond 7) Li & F

8) K & O

9) Mg & Cl

10) Mg & S