Lesson 8: Wrap-Up

Now that you have worked your way through this lesson you should be able to figure out what type of bonding will hold together any collection of atoms. You should also be able to figure out whether those atoms will bond together as molecules or networks. In addition, you should be able to figure out whether they will bond together as an element, an alloy or a compound. Of course, if it is a compound, you should be able to name it. Throughout all of this you should be able to explain what happens to the electrons of individual, isolated atoms when they come in contact with and fall under the influence of other atoms because that is what bonding is all about.

covalent - ionic - metallic

molecules - networks

element - alloy - compound

name compounds

what happens to electrons

To help you practice these things I suggest you work through exercises 23 and 24 in your workbook. You can check your answers with the instructor.

If you haven't done them already, work on the computer practice program for covalent nomenclature. (You need to complete 30 correctly for full credit. There is no penalty for wrong answers. Although the minimum is 30 correct, do as many as you need to become adept at naming covalent compounds.) Be sure to print out the record of your practice sessions to turn in as your lab work this week.

After that, I recommend that you review the objectives for this lesson and take the self-quiz for practice, and do the problem set.

Self Quiz | Self Quiz Answers

Self Quiz

1. Draw an electron dot diagram for H₂O. What is represented by each portion of the diagram?

2. Metallic bonding involves:

a.         atoms which have gained electrons being attracted to the opposite charge of atoms which have lost electrons
b.         atoms sharing tightly held electrons between them
c.          atoms sharing very loosely held electrons

3. What is the correct formula for nitrogen? What is represented by each of the incorrect answers?

a.         N₃

b.         N²

c.          N

d.         N₂

e.         N^3-

4. What is the bond type and formula of the compound formed by sodium and oxygen?

5. How many electrons are there in a single bond?

a.         6
b.         3
c.          2
d.         1
e.         4

6. Bonding between Si and O will result in:

a. a molecular material
b. a network material

7. What is the bond type (ionic, covalent, or metallic) and formula of the compound you would expect to form between nitrogen and chlorine?

8. According to the octet rule, atoms want to:

a.         end up with eight electrons
b.         gain eight electrons
c.          lose eight electrons
d.         end up with eight valence electrons

9. When dealing with polyatomic ions, covalent bonding is the attraction that holds:

a. one polyatomic ion to another
b. one atom to another in an ion

10. Electronegativity increases as you:

a.         go across a period (L to R)
b.         go down a group
c.          go up a group
d.         both a and c
e.         a, b, and c

11. Give the name or the formula for the following two compounds:

a. PI₃

b. dinitrogen monoxide

12. In order to determine what type of name to use for a compound, a chemist must first determine

a. whether the compound is covalently or ionically bonded.
b. whether the compound is polar or non-polar.
c. whether the compound adopts a molecular or network structure.

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Self Quiz Answers

1. Draw an electron dot diagram for H₂O. What is represented by each portion of the diagram?

··
H : O : H
··
H - hydrogen atom
O - oxygen atom
: - polar covalent bond between H and O
( ·· - unbonded pair of electrons)

2. Metallic bonding involves:

** c. atoms sharing very loosely held electrons

3. What is the correct formula for nitrogen? What is represented by each of the incorrect answers?

a. N₃ - formula for a molecule containing 3 N atoms, but nitrogen is diatomic

b. N² - the "2" should be a subscript, unless it is a charge, then it should have a "+" or "-"

c. N - symbol for (an atom of) nitrogen

**d. N₂ - correct (nitrogen is one of the diatomic elements)

e. N^3- - formula for nitride ion

4. What is the bond type and formula of the compound formed by sodium and oxygen?

ionic, Na₂O

5. How many electrons are there in a single bond?

**c. 2

6. Bonding between Si and O will result in:

**b. a network material

7. What is the bond type and formula of the compound you would expect to form between nitrogen and chlorine?

covalent, NCl₃

8. According to the octet rule, atoms want to:

**d. end up with eight valence electrons

9. When dealing with polyatomic ions, covalent bonding is the attraction that holds:

**b. one atom to another in an ion

10. Electronegativity increases as you:

** d. both a and c