Which of the following can lose two electrons to attain the configuration of argon?

Options

A. Mg
B. Br
C. S
D. Ca

Explanation

To determine which element can lose two electrons to attain the electron configuration of argon, we first need to understand the electron configuration of argon and the elements in question.

### Step-by-Step Solution:

1. **Identify the Electron Configuration of Argon**:
- Argon (Ar) has an atomic number of 18, meaning it has 18 electrons. Its electron configuration is \(1s^2 2s^2 2p^6 3s^2 3p^6\). The outermost shell (the third shell) contains 8 electrons (2 in 3s and 6 in 3p).

2. **List the Elements and Their Atomic Numbers**:
- We need to consider the elements provided in the options (not specified in the question but typically include elements like calcium, sulfur, bromine, etc.):
- Calcium (Ca) - Atomic number 20
- Sulfur (S) - Atomic number 16
- Bromine (Br) - Atomic number 35

3. **Determine the Electron Configuration of Each Element**:
- **Calcium (Ca)**:
- Configuration: \(1s^2 2s^2 2p^6 3s^2 3p^6 4s^2\) (20 electrons)
- If it loses 2 electrons from the 4s subshell, it will have 18 electrons, attaining the configuration of argon.
- **Sulfur (S)**:
- Configuration: \(1s^2 2s^2 2p^6 3s^2 3p^4\) (16 electrons)
- If it loses 2 electrons, it will have 14 electrons, which does not match argon.
- **Bromine (Br)**:
- Configuration: \(1s^2 2s^2 2p^6 3s^2 3p^6 4s^2 3d^{10} 4p^5\) (35 electrons)
- If it loses 2 electrons, it will have 33 electrons, which does not match argon.

4. **Conclusion**:
- From the analysis, only **Calcium (Ca)** can lose 2 electrons to attain the electron configuration of argon.

### Final Answer:
- The element that can lose two electrons to attain the configuration of argon is **Calcium (Ca)**.