Use with Chapter 7,Section 7.4

Name______________________________________________ Date______________________ Class_____________________

TEACHING TRANSPARENCY 25

Metallic Bonding

Chemistry: Matter and Change Teaching Transparency1

Use with Chapter 7,Section 7.4

Name______________________________________________ Date______________________ Class_____________________

TEACHING TRANSPARENCY 25

Metallic Bonding1. What is a regular, repeating three-dimensional arrangement of atoms called?

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2. Do the separate electrons that are shown belong exclusively to a single atom? What word is used to describe such electrons?______________________________________________________________________________________________

3. Are the electrons shown the only ones actually present? Explain.______________________________________________________________________________________________

4. Why are the central atoms shown as positively charged?______________________________________________________________________________________________

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5. How does the number of separate electrons shown for the group 1 metal atoms compare to the number of atoms? Explain why in terms of valence electrons.______________________________________________________________________________________________

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6. How does the number of separate electrons shown for the group 2 metal atoms compare to the number of atoms?______________________________________________________________________________________________

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7. What holds the metal atoms together in such an arrangement?______________________________________________________________________________________________

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8. What term is used to describe this model of metallic bonding? ___________________________________________

9. How well do metals tend to conduct electricity? How does the model of metallic bonding account for that property?______________________________________________________________________________________________

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10. Do metals tend to be brittle, or are they malleable and ductile? How does the model of metallic bonding account for that property? ______________________________________________________________________________________________

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Chemistry: Matter and Change Teaching Transparency Worksheet2

TEACHER GUIDE AND ANSWERS

Teaching Transparency 25 – Metallic Bonding

1. a crystal lattice2. no; delocalized3. No; they are the valence electrons from the metal

atoms.4. The delocalized negative electrons came from neutral

atoms, thus leaving the atoms with a positive charge.5. They are equal. Group 1 atoms have only one valence

electron and thus only one electron that can become delocalized.

6. There are twice as many electrons as group 2 atoms.

7. The delocalized electrons are simultaneously attracted to more than one metal cation.

8. electron sea model9. Metals tend to conduct electricity well. The model’s

delocalized electrons are not held strongly by individual atoms and are thus able to move easily throughout the metal.

10. Metals are malleable and ductile. The model’s delocalized electrons are able to move around the positive metal core atoms and keep the crystal from breaking during hammering or drawing into wire.

Chemistry: Matter and Change Teacher Guide and Answers3