A neutral atom of an element has `2K,8L` and `5M` electron .Find out the following
Maximum number of electron having same spin

Options

A. 5
B. 8
C. 9
D. 3

Explanation

To find the maximum number of electrons having the same spin in a neutral atom with the given electron configuration of `2K, 8L, and 5M`, we can follow these steps:

### Step 1: Identify the total number of electrons
The total number of electrons in the atom is the sum of the electrons in each shell:
- K shell: 2 electrons
- L shell: 8 electrons
- M shell: 5 electrons

Total electrons = 2 + 8 + 5 = **15 electrons**

### Step 2: Write the electronic configuration
The electronic configuration can be written based on the distribution of electrons in the orbitals:
- 1s² (2 electrons)
- 2s² (2 electrons)
- 2p⁶ (6 electrons)
- 3s² (2 electrons)
- 3p³ (3 electrons)

Thus, the electronic configuration is: **1s² 2s² 2p⁶ 3s² 3p³**

### Step 3: Fill the orbitals and determine the spins
Now, we will fill the orbitals and note the spins:
- **1s²**: 2 electrons with opposite spins (1 spin up, 1 spin down)
- **2s²**: 2 electrons with opposite spins (1 spin up, 1 spin down)
- **2p⁶**: 6 electrons with opposite spins (3 spin up, 3 spin down)
- **3s²**: 2 electrons with opposite spins (1 spin up, 1 spin down)
- **3p³**: 3 electrons (following Hund's rule, they will have the same spin) (3 spin up)

### Step 4: Count the electrons with the same spin
Now, let’s count the total number of electrons with the same spin:
- Spin up (+1/2):
- 1s: 1
- 2s: 1
- 2p: 3
- 3s: 1
- 3p: 3
- Total: 1 + 1 + 3 + 1 + 3 = **9 electrons**

- Spin down (-1/2):
- 1s: 1
- 2s: 1
- 2p: 3
- 3s: 1
- 3p: 0
- Total: 1 + 1 + 3 + 1 + 0 = **6 electrons**

### Conclusion
The maximum number of electrons that can have the same spin in this atom is **9 electrons** with spin +1/2.

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