Which is /are correct statement ?

Options

A. (a) Number of subshell present in M-shell`=3`
B. (b) Number of orbitals present in N-shell `=16`
C. (c) `Cu^(+) (z=29)` is paramagnetic
D. (d) Zeeman effect explains splitting of
spectral lines in magnetic field.

Answer

To determine which statements are correct, we will analyze each statement step by step.

### Step 1: Analyze the first statement
**Statement:** The number of subshells present in the M shell is 3.

- The principal quantum number (n) for the M shell is 3.
- The azimuthal quantum number (l) can take values from 0 to n-1. Thus, for n = 3, l can be 0, 1, or 2.
- These correspond to the subshells:
- l = 0 (s subshell)
- l = 1 (p subshell)
- l = 2 (d subshell)
- Therefore, there are 3 subshells in the M shell.

**Conclusion:** This statement is **correct**.

### Step 2: Analyze the second statement
**Statement:** The number of orbitals present in the N shell is 16.

- The principal quantum number (n) for the N shell is 4.
- The azimuthal quantum number (l) can take values from 0 to n-1. Thus, for n = 4, l can be 0, 1, 2, or 3.
- The subshells corresponding to these values are:
- l = 0 (s subshell) has 1 orbital
- l = 1 (p subshell) has 3 orbitals
- l = 2 (d subshell) has 5 orbitals
- l = 3 (f subshell) has 7 orbitals
- Adding these gives: 1 (s) + 3 (p) + 5 (d) + 7 (f) = 16 orbitals.

**Conclusion:** This statement is **correct**.

### Step 3: Analyze the third statement
**Statement:** Copper (Cu) with atomic number 29 is paramagnetic.

- The electronic configuration of neutral copper (Cu) is:
- 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹ 3d¹⁰.
- For the Cu⁺ ion (copper positive), one electron is removed from the 4s subshell:
- Cu⁺: 1s² 2s² 2p⁶ 3s² 3p⁶ 3d¹⁰.
- In Cu⁺, the 3d subshell is fully filled (10 electrons), meaning all electrons are paired.
- Paramagnetic substances have unpaired electrons, while diamagnetic substances have all paired electrons.

**Conclusion:** This statement is **incorrect** (Cu⁺ is diamagnetic).

### Step 4: Analyze the fourth statement
**Statement:** The Zeeman effect explains the splitting of spectral lines in a magnetic field.

- The Zeeman effect refers to the phenomenon where spectral lines are split into multiple components in the presence of a magnetic field due to the interaction between magnetic moments and the external magnetic field.
- This statement is accurate.

**Conclusion:** This statement is **correct**.

### Final Summary of Correct Statements
- The correct statements are:
- Statement 1: Correct
- Statement 2: Correct
- Statement 3: Incorrect
- Statement 4: Correct

Thus, the correct statements are 1, 2, and 4.

---