Maximum number of electrons that can be present in M and N - shells respectively are

Options

A. 18, 32
B. 8, 18
C. 32, 50
D. 32, 48

Answer

To find the maximum number of electrons that can be present in the M and N shells, we can use the formula:

**Step 1: Understand the formula for maximum electrons in a shell.**
The formula to calculate the maximum number of electrons in a shell is given by:
\[ \text{Maximum electrons} = 2n^2 \]
where \( n \) is the principal quantum number corresponding to the shell.

**Step 2: Identify the principal quantum numbers for M and N shells.**
- For the M shell, the principal quantum number \( n = 3 \).
- For the N shell, the principal quantum number \( n = 4 \).

**Step 3: Calculate the maximum number of electrons in the M shell.**
Using the formula for the M shell:
\[ \text{Maximum electrons in M shell} = 2n^2 = 2(3^2) = 2(9) = 18 \]

**Step 4: Calculate the maximum number of electrons in the N shell.**
Using the formula for the N shell:
\[ \text{Maximum electrons in N shell} = 2n^2 = 2(4^2) = 2(16) = 32 \]

**Step 5: State the final answer.**
Thus, the maximum number of electrons that can be present in the M shell is 18 and in the N shell is 32.

**Final Answer:**
- Maximum number of electrons in M shell: **18**
- Maximum number of electrons in N shell: **32**

---