How many electrons in calcium have l = 0 ?

Options

A. 6
B. 8
C. 10
D. 12

Answer

To solve the question of how many electrons in calcium have the azimuthal quantum number \( l = 0 \), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Atomic Number of Calcium**:
- Calcium has an atomic number of 20. This means it has 20 electrons.

2. **Write the Electron Configuration**:
- The electron configuration of calcium can be written as:
\[ \text{Calcium: } 1s^2, 2s^2, 2p^6, 3s^2, 3p^6, 4s^2 \]

3. **Understand the Azimuthal Quantum Number \( l \)**:
- The azimuthal quantum number \( l \) describes the shape of the orbital. For \( l = 0 \), the corresponding subshell is the **s subshell**.

4. **Count the Electrons in the S Subshells**:
- From the electron configuration:
- The \( 1s \) subshell has 2 electrons.
- The \( 2s \) subshell has 2 electrons.
- The \( 3s \) subshell has 2 electrons.
- The \( 4s \) subshell has 2 electrons.
- Therefore, the total number of electrons in all the s subshells is:
\[ 2 (1s) + 2 (2s) + 2 (3s) + 2 (4s) = 8 \text{ electrons} \]

5. **Conclusion**:
- The total number of electrons in calcium that have \( l = 0 \) is **8**.

### Final Answer:
The number of electrons in calcium that have \( l = 0 \) is **8**.

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