How many electrons are gained or lost by calcium to attain nearest noble gas configuration ?

Options

A. 2 electrons gain
B. 2 electrons lost
C. 3 electrons gain
D. 3 electrons lost

Explanation

To determine how many electrons are gained or lost by calcium to attain the nearest noble gas configuration, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Atomic Number of Calcium**:
- The atomic number of calcium (Ca) is 20.

2. **Write the Electronic Configuration of Calcium**:
- The electronic configuration of calcium is:
\[ 1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^6 \, 4s^2 \]
- This can be simplified to:
\[ [Ar] \, 4s^2 \]
- Here, [Ar] represents the electron configuration of Argon, which is the nearest noble gas.

3. **Determine the Nearest Noble Gas Configuration**:
- The nearest noble gas to calcium is Argon (Ar), which has an electronic configuration of:
\[ 1s^2 \, 2s^2 \, 2p^6 \, 3s^2 \, 3p^6 \]
- This configuration has a total of 18 electrons.

4. **Analyze the Valence Electrons**:
- Calcium has 2 electrons in its outermost shell (4s^2).
- To achieve the noble gas configuration of Argon, calcium needs to have a total of 8 electrons in its outermost shell.

5. **Determine the Electrons to be Gained or Lost**:
- Since calcium has 2 electrons in its outermost shell and needs to lose these 2 electrons to reach the stable configuration of Argon, it will lose 2 electrons.
- Gaining 6 electrons would be difficult for calcium, as it would require adding electrons to the 4s and 3p orbitals.

6. **Conclusion**:
- Therefore, calcium loses 2 electrons to attain the nearest noble gas configuration.

### Final Answer:
Calcium loses **2 electrons** to attain the nearest noble gas configuration.

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