Number of which among the following is same in `Al^(3+)` and `F^(-)` ?

Options

A. Proton
B. Neutron
C. Atomic mass
D. Electron

Explanation

To solve the question of which number is the same in \( \text{Al}^{3+} \) and \( \text{F}^{-} \), we need to analyze the atomic structure of both ions.

### Step 1: Determine the number of protons in \( \text{Al}^{3+} \) and \( \text{F}^{-} \)

- **Aluminum (Al)** has an atomic number of 13, which means it has **13 protons**.
- **Fluorine (F)** has an atomic number of 9, which means it has **9 protons**.

### Step 2: Determine the number of electrons in \( \text{Al}^{3+} \) and \( \text{F}^{-} \)

- For \( \text{Al}^{3+} \): Since it has a +3 charge, it has lost 3 electrons. Therefore, the number of electrons is:
\[ 13 \text{ (protons)} - 3 = 10 \text{ electrons} \]

- For \( \text{F}^{-} \): Since it has a -1 charge, it has gained 1 electron. Therefore, the number of electrons is:
\[ 9 \text{ (protons)} + 1 = 10 \text{ electrons} \]

### Step 3: Determine the number of neutrons in \( \text{Al}^{3+} \) and \( \text{F}^{-} \)

- The number of neutrons can be calculated using the formula:
\[ \text{Neutrons} = \text{Mass number} - \text{Protons} \]

- For \( \text{Al}^{3+} \): The most common isotope of aluminum has a mass number of 27.
\[ \text{Neutrons} = 27 - 13 = 14 \]

- For \( \text{F}^{-} \): The most common isotope of fluorine has a mass number of 19.
\[ \text{Neutrons} = 19 - 9 = 10 \]

### Step 4: Compare the values

- **Protons**: \( \text{Al}^{3+} \) has 13 protons, \( \text{F}^{-} \) has 9 protons (not the same).
- **Electrons**: Both \( \text{Al}^{3+} \) and \( \text{F}^{-} \) have 10 electrons (same).
- **Neutrons**: \( \text{Al}^{3+} \) has 14 neutrons, \( \text{F}^{-} \) has 10 neutrons (not the same).

### Conclusion

The number of electrons is the same in both \( \text{Al}^{3+} \) and \( \text{F}^{-} \), which is 10.

---