Question

According to Bohr model, the maximum number of electrons occupying M-shell will be

• A. 6
• B. 5
• C. 9
• D. 18

Hint:

The formula \(2n^2\) helps you quickly determine the maximum number of electrons a shell can hold. For the M-shell (\(n=3\)), the result is 18.

Answer 1

The Correct Option is D

Step 1: Recall that the Bohr model describes electron arrangement in shells, where the maximum number of electrons that can occupy a given shell is given by the formula: \[ \text{Maximum number of electrons} = 2n^2 \] where \(n\) is the shell number.

Step 2: For the M-shell, which is the third shell (\(n = 3\)): \[ \text{Maximum number of electrons} = 2 \times 3^2 = 2 \times 9 = 18 \]

Step 3: Therefore, the maximum number of electrons in the M-shell is 18.

Step 4: Since the M-shell can hold a maximum of 18 electrons, the correct answer is (4) 18.