Which metal has 2 electrons in the outermost orbit

Options

A. Na
B. Cu
C. Au
D. Be

Explanation

To determine which metal has 2 electrons in its outermost orbit, we can analyze the electronic configurations of the given options: Sodium, Copper, Gold, and Beryllium.

### Step-by-Step Solution:

1. **Identify the Elements and Their Atomic Numbers**:
- Sodium (Na) - Atomic Number 11
- Copper (Cu) - Atomic Number 29
- Gold (Au) - Atomic Number 79
- Beryllium (Be) - Atomic Number 4

2. **Write the Electronic Configurations**:
- **Sodium (Na)**:
- Electronic Configuration: 1s² 2s² 2p⁶ 3s¹
- Outermost shell (n=3): 3s¹ → 1 electron
- **Copper (Cu)**:
- Electronic Configuration: [Ar] 4s¹ 3d¹⁰
- Outermost shell (n=4): 4s¹ → 1 electron
- **Gold (Au)**:
- Electronic Configuration: [Xe] 4f¹⁴ 5d¹⁰ 6s¹
- Outermost shell (n=6): 6s¹ → 1 electron
- **Beryllium (Be)**:
- Electronic Configuration: 1s² 2s²
- Outermost shell (n=2): 2s² → 2 electrons

3. **Count the Electrons in the Outermost Shell**:
- Sodium: 1 electron
- Copper: 1 electron
- Gold: 1 electron
- Beryllium: 2 electrons

4. **Identify the Metal with 2 Electrons in the Outermost Shell**:
- From the analysis, Beryllium (Be) is the only metal that has 2 electrons in its outermost shell.

### Conclusion:
The metal that has 2 electrons in the outermost orbit is **Beryllium (Be)**.

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