Valence Electron Lesson Plans & Worksheets Reviewed by Teachers - Free Printable

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Let’s go through each part step by step.

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Part 1: Fill in the blanks

1. In the periodic table, each row is called a _________.
✔ Answer: *Period*
> Each horizontal row in the periodic table is called a period. There are 7 periods in total.

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2. Each column in the periodic table is called a _________.
✔ Answer: *Group*
> Vertical columns are called groups. Elements in the same group have similar chemical properties.

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3. Each element in the periodic table is called a _________.
✔ Answer: *Chemical element* (or simply "element")
> Each box represents one chemical element.

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4. The electrons in the outer shell are called _________.
✔ Answer: *Valence electrons*
> These are the electrons in the outermost shell and determine how an atom bonds with others.

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5. The electrons in the same shell are called _________ electrons.
✔ Answer: *Energy level electrons* or *shell electrons*
> More precisely, electrons in the same shell occupy the same energy level.

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6. The number of shells equals the _________ of the period.
✔ Answer: *Number*
> The period number tells you how many electron shells (energy levels) the atom has.

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Part 2: Complete the chart

We need to fill in the following for each element:

| Symbol | Element | Period | # of Shells | Group # | Valence electrons |
|--------|---------|--------|-------------|---------|-------------------|
| C | Carbon | 2 | 2 | 14 | 4 |
| Na | Sodium | 3 | 3 | 1 | 1 |
| Ne | Neon | 2 | 2 | 18 | 8 |
| Al | Aluminum| 3 | 3 | 13 | 3 |
| Ba | Barium | 6 | 6 | 2 | 2 |
| Br | Bromine | 4 | 4 | 17 | 7 |

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#### Explanation for each row:

1. C (Carbon)
- Period: 2 → 2 shells
- Group: 14 → valence electrons = 4
- Electron configuration: 1s² 2s² 2p² → outer shell (n=2) has 4 electrons

2. Na (Sodium)
- Period: 3 → 3 shells
- Group: 1 → valence electrons = 1
- Configuration: [Ne] 3s¹ → outer shell has 1 electron

3. Ne (Neon)
- Period: 2 → 2 shells
- Group: 18 (Noble gas) → valence electrons = 8 (full octet)
- Configuration: 1s² 2s² 2p⁶ → outer shell (n=2) has 8 electrons

4. Al (Aluminum)
- Period: 3 → 3 shells
- Group: 13 → valence electrons = 3
- Configuration: [Ne] 3s² 3p¹ → 3 valence electrons

5. Ba (Barium)
- Period: 6 → 6 shells
- Group: 2 → valence electrons = 2
- Configuration: [Xe] 6s² → 2 valence electrons

6. Br (Bromine)
- Period: 4 → 4 shells
- Group: 17 → valence electrons = 7
- Configuration: [Ar] 4s² 3d¹⁰ 4p⁵ → outer shell (n=4) has 7 electrons

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✔ Final Answer Summary:

Fill-in-the-blanks:
1. Period
2. Group
3. Element
4. Valence electrons
5. Shell (or energy level)
6. Number

Chart:

| Symbol | Element | Period | # of Shells | Group # | Valence electrons |
|--------|-----------|--------|-------------|---------|-------------------|
| C | Carbon | 2 | 2 | 14 | 4 |
| Na | Sodium | 3 | 3 | 1 | 1 |
| Ne | Neon | 2 | 2 | 18 | 8 |
| Al | Aluminum | 3 | 3 | 13 | 3 |
| Ba | Barium | 6 | 6 | 2 | 2 |
| Br | Bromine | 4 | 4 | 17 | 7 |

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Let me know if you'd like a printable version or further explanation about electron configurations!