In how many elements the last electron will have the following set of quantum numbers, n = 3 and l = 1?

Options

A. 2
B. 8
C. 6
D. 10

Explanation

To determine how many elements have the last electron with the quantum numbers \( n = 3 \) and \( l = 1 \), we will follow these steps:

### Step 1: Understand the Quantum Numbers
The principal quantum number \( n \) indicates the energy level or shell of an electron. Here, \( n = 3 \) means we are looking at the third shell.

The azimuthal quantum number \( l \) indicates the subshell or type of orbital. For \( l = 1 \), we are referring to the p-orbital.

### Step 2: Identify the Electron Configuration
The p-orbital can hold a maximum of 6 electrons. Therefore, the possible electron configurations for the p-orbital in the third shell are:

- \( 3p^1 \)
- \( 3p^2 \)
- \( 3p^3 \)
- \( 3p^4 \)
- \( 3p^5 \)
- \( 3p^6 \)

### Step 3: Count the Elements
Each configuration corresponds to a different element. Starting from the first element in the p-block of the periodic table:

1. \( 3p^1 \) - Scandium (Sc)
2. \( 3p^2 \) - Titanium (Ti)
3. \( 3p^3 \) - Vanadium (V)
4. \( 3p^4 \) - Chromium (Cr)
5. \( 3p^5 \) - Manganese (Mn)
6. \( 3p^6 \) - Iron (Fe)

Thus, the last electron can occupy the \( 3p \) subshell for a total of 6 elements.

### Conclusion
The total number of elements where the last electron will have the quantum numbers \( n = 3 \) and \( l = 1 \) is **6**.

### Final Answer
**6 elements**

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