For Rb(Z = 37), points out the number of electrons present in L and N shells respectively

Options

A. 8 and 18
B. 18 and 8
C. 8 and 8
D. 2 and 8

Answer

To determine the number of electrons present in the L and N shells for rubidium (Rb) with atomic number Z = 37, we can follow these steps:

### Step 1: Identify the Electron Configuration
The atomic number of rubidium (Rb) is 37, which means it has 37 electrons. The electron configuration is filled according to the order of increasing energy levels (K, L, M, N, etc.).

### Step 2: Determine the Maximum Number of Electrons in Each Shell
Using the formula \(2n^2\), we can calculate the maximum number of electrons that can be accommodated in each shell:
- **K shell (n=1)**: \(2(1^2) = 2\) electrons
- **L shell (n=2)**: \(2(2^2) = 8\) electrons
- **M shell (n=3)**: \(2(3^2) = 18\) electrons
- **N shell (n=4)**: \(2(4^2) = 32\) electrons

### Step 3: Fill Electrons in Each Shell
Now, let's fill the electrons in the shells according to the maximum capacity:
1. **K shell**: 2 electrons (filled)
2. **L shell**: 8 electrons (filled)
3. **M shell**: 18 electrons (filled)

At this point, we have filled:
- K shell: 2 electrons
- L shell: 8 electrons
- M shell: 18 electrons

Total filled = \(2 + 8 + 18 = 28\) electrons.

### Step 4: Determine Remaining Electrons
After filling the K, L, and M shells, we have:
- Total electrons: 37
- Electrons filled: 28
- Remaining electrons: \(37 - 28 = 9\)

### Step 5: Fill the N Shell
The N shell can hold a maximum of 32 electrons, but we only have 9 electrons left to fill. Therefore, we can place 9 electrons in the N shell.

### Step 6: Conclusion
- **Electrons in L shell**: 8
- **Electrons in N shell**: 9

Thus, the number of electrons present in the L and N shells for rubidium (Rb) is:
- L shell: 8 electrons
- N shell: 9 electrons