Three quantum numbers are required to define an orbital while four quantum numbers are required to describe an electron.
`(n + l)` is maximum and minimum for which of the following orbitals: `6s, 5p, 6d, 4d, 2p, 3s, 2s`? 

Options

A. `6f and 2s`
B. `6d and 2s`
C. `5p and 3s`
D. `6s and 2p`

Answer

To solve the problem, we need to calculate the \( n + l \) values for each of the given orbitals and then identify which one has the maximum and minimum values.

### Step-by-Step Solution:

1. **Identify the Quantum Numbers**:
- The principal quantum number \( n \) indicates the energy level of the electron.
- The azimuthal quantum number \( l \) corresponds to the type of orbital:
- \( s \) orbitals have \( l = 0 \)
- \( p \) orbitals have \( l = 1 \)
- \( d \) orbitals have \( l = 2 \)
- \( f \) orbitals have \( l = 3 \)

2. **Calculate \( n + l \) for Each Orbital**:
- **For 6s**:
- \( n = 6 \), \( l = 0 \)
- \( n + l = 6 + 0 = 6 \)
- **For 5p**:
- \( n = 5 \), \( l = 1 \)
- \( n + l = 5 + 1 = 6 \)
- **For 6d**:
- \( n = 6 \), \( l = 2 \)
- \( n + l = 6 + 2 = 8 \)
- **For 4d**:
- \( n = 4 \), \( l = 2 \)
- \( n + l = 4 + 2 = 6 \)
- **For 2p**:
- \( n = 2 \), \( l = 1 \)
- \( n + l = 2 + 1 = 3 \)
- **For 3s**:
- \( n = 3 \), \( l = 0 \)
- \( n + l = 3 + 0 = 3 \)
- **For 2s**:
- \( n = 2 \), \( l = 0 \)
- \( n + l = 2 + 0 = 2 \)

3. **Summarize the \( n + l \) Values**:
- 6s: \( n + l = 6 \)
- 5p: \( n + l = 6 \)
- 6d: \( n + l = 8 \)
- 4d: \( n + l = 6 \)
- 2p: \( n + l = 3 \)
- 3s: \( n + l = 3 \)
- 2s: \( n + l = 2 \)

4. **Determine Maximum and Minimum**:
- **Maximum \( n + l \)**: The maximum value is \( 8 \) from the **6d** orbital.
- **Minimum \( n + l \)**: The minimum value is \( 2 \) from the **2s** orbital.

### Final Answer:
- Maximum \( n + l \) is for **6d**.
- Minimum \( n + l \) is for **2s**.