Which one of the following statement (s) is (are) correct?

Options

A. The electronic configuration of Cr is [Ar] `3d^(5)4s^(1)`. (Atomic No. of Cr= 24)
B. The magnetic quantum number may have a negative value
C. In silver atom, 23 electrons have a spin of one type and 24 of the opposite type. (Atomic No. of Ag=47)
D. The oxidation state of nitrogen in `HN_(3)` is -3

Answer

To determine which statements are correct, we will analyze each statement one by one based on the information provided in the video transcript.

### Step-by-Step Solution:

1. **Understanding the Electronic Configuration of Chromium:**
- Chromium (Cr) has an atomic number of 24.
- Its electronic configuration is [Ar] 3d^5 4s^1.
- The 3d subshell is half-filled, which is more stable than a partially filled subshell.
- **Conclusion:** The first statement regarding chromium's electronic configuration is correct.

2. **Magnetic Quantum Number (m_l):**
- The magnetic quantum number (m_l) can take values from -l to +l, where l is the azimuthal quantum number.
- For any given l, m_l can indeed be negative.
- Therefore, the second statement about the magnetic quantum number having a negative value is correct.

3. **Electrons in Silver Atom:**
- The question states that in a silver atom, 23 electrons have a spin of one type and 24 of the opposite type.
- The total number of electrons mentioned is 23 + 24 = 47, which is incorrect because silver (Ag) has an atomic number of 47, meaning it has 47 electrons.
- Thus, the statement about the distribution of spins in silver is misleading, as it doesn't accurately reflect the electron configuration.
- **Conclusion:** The third statement is incorrect.

4. **Oxidation State of Nitrogen in HN3:**
- In hydrazoic acid (HN3), nitrogen does not have an oxidation state of -3.
- The oxidation state of nitrogen in HN3 is actually +1.
- Therefore, the statement regarding the oxidation state of nitrogen in HN3 is incorrect.
- **Conclusion:** The fourth statement is incorrect.

### Final Conclusion:
- The correct statements are:
- Statement 1: Correct (about chromium's electronic configuration).
- Statement 2: Correct (about the magnetic quantum number).
- Statement 3: Incorrect (about silver's electron spins).
- Statement 4: Incorrect (about the oxidation state of nitrogen in HN3).

### Summary of Correct Statements:
- Statements 1 and 2 are correct.