Tripositive ion, i.e., X+3 has 13 protons and 14 neutrons. Calculate the number of electrons present in the M shell of the neutral atom.

Options

A. 2
B. 1
C. 3
D. 5

Explanation

To solve the question about the tripositive ion \( X^{3+} \) with 13 protons and 14 neutrons and to find the number of electrons in the M shell of the neutral atom, follow these steps:

### Step 1: Determine the number of electrons in the neutral atom.
- A neutral atom has an equal number of protons and electrons. Since the ion \( X^{3+} \) has 13 protons, the neutral atom will also have 13 electrons.

### Step 2: Understand the electron configuration.
- The electron configuration is filled according to the shells:
- K shell can hold a maximum of 2 electrons.
- L shell can hold a maximum of 8 electrons.
- M shell can hold a maximum of 18 electrons.

### Step 3: Fill the K and L shells.
- Fill the K shell first:
- K shell: 2 electrons
- Fill the L shell next:
- L shell: 8 electrons
- Total electrons used so far: \( 2 + 8 = 10 \)

### Step 4: Calculate the remaining electrons for the M shell.
- Since the neutral atom has 13 electrons and we have already placed 10 in the K and L shells, the remaining electrons will go into the M shell:
- Remaining electrons = \( 13 - 10 = 3 \)

### Conclusion:
- Therefore, the number of electrons present in the M shell of the neutral atom is **3**.