Covalent Bonds Worksheet Answer Key - Free Printable

Covalent Bonding Worksheet Solution and Explanation

The worksheet focuses on covalent bonding, where non-metal atoms share electrons to achieve a stable electron configuration (usually 8 valence electrons). Below is the step-by-step solution for each problem, along with explanations.

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#### 1. Hydrogen (H₂)
- Molecular Formula: H₂
- Lewis Dot Diagram:
- Each hydrogen atom has 1 valence electron.
- To achieve stability, they share their electrons, forming a single bond.
- Lewis Dot Diagram:
```
H : H
```
or
```
H-H
```

#### 2. Fluorine (F₂)
- Molecular Formula: F₂
- Lewis Dot Diagram:
- Each fluorine atom has 7 valence electrons.
- They share one pair of electrons to achieve an octet.
- Lewis Dot Diagram:
```
F : F
```
or
```
F-F
```

#### 3. Oxygen (O₂)
- Molecular Formula: O₂
- Lewis Dot Diagram:
- Each oxygen atom has 6 valence electrons.
- To achieve stability, they share two pairs of electrons, forming a double bond.
- Lewis Dot Diagram:
```
O = O
```

#### 4. Nitrogen (N₂)
- Molecular Formula: N₂
- Lewis Dot Diagram:
- Each nitrogen atom has 5 valence electrons.
- To achieve stability, they share three pairs of electrons, forming a triple bond.
- Lewis Dot Diagram:
```
N ≡ N
```

#### 5. Boron Trifluoride (BF₃)
- Molecular Formula: BF₃
- Lewis Dot Diagram:
- Boron (B) has 3 valence electrons.
- Each fluorine (F) has 7 valence electrons.
- Boron shares one electron with each of the three fluorine atoms.
- Lewis Dot Diagram:
```
F
|
F-B-F
|
F
```

#### 6. Ammonia (NH₃)
- Molecular Formula: NH₃
- Lewis Dot Diagram:
- Nitrogen (N) has 5 valence electrons.
- Each hydrogen (H) has 1 valence electron.
- Nitrogen shares one electron with each of the three hydrogen atoms.
- Lewis Dot Diagram:
```
H
/
H-N-H
\
H
```

#### 7. Carbon Dioxide (CO₂)
- Molecular Formula: CO₂
- Lewis Dot Diagram:
- Carbon (C) has 4 valence electrons.
- Each oxygen (O) has 6 valence electrons.
- Carbon forms double bonds with both oxygen atoms.
- Lewis Dot Diagram:
```
O = C = O
```

#### 8. Methane (CH₄)
- Molecular Formula: CH₄
- Lewis Dot Diagram:
- Carbon (C) has 4 valence electrons.
- Each hydrogen (H) has 1 valence electron.
- Carbon shares one electron with each of the four hydrogen atoms.
- Lewis Dot Diagram:
```
H
/
H-C-H
\
H
```

#### 9. Dihydrogen Monoxide (H₂O)
- Molecular Formula: H₂O
- Lewis Dot Diagram:
- Oxygen (O) has 6 valence electrons.
- Each hydrogen (H) has 1 valence electron.
- Oxygen forms single bonds with both hydrogen atoms.
- Lewis Dot Diagram:
```
H
/
O-H
```

#### 10. Sulfur Dioxide (SO₂)
- Molecular Formula: SO₂
- Lewis Dot Diagram:
- Sulfur (S) has 6 valence electrons.
- Each oxygen (O) has 6 valence electrons.
- Sulfur forms double bonds with both oxygen atoms.
- Note: One lone pair of electrons remains on sulfur.
- Lewis Dot Diagram:
```
O = S = O
```

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Final Answer Summary:

1. H₂:
```
H-H
```

2. F₂:
```
F-F
```

3. O₂:
```
O=O
```

4. N₂:
```
N≡N
```

5. BF₃:
```
F
|
F-B-F
|
F
```

6. NH₃:
```
H
/
H-N-H
\
H
```

7. CO₂:
```
O=C=O
```

8. CH₄:
```
H
/
H-C-H
\
H
```

9. H₂O:
```
H
/
O-H
```

10. SO₂:
```
O=S=O
```

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Final Answer:
\boxed{\text{See detailed solutions above}}