The number of which subatomic particle is same in case of chlorine atom and chloride ion?

Options

A. Electron
B. Proton
C. Neutrons
D. All of the above

Explanation

To determine which subatomic particle has the same number in both a chlorine atom (Cl) and a chloride ion (Cl⁻), we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Subatomic Particles**: The three main subatomic particles are protons, neutrons, and electrons. We need to analyze how these particles behave in a chlorine atom and a chloride ion.

2. **Determine the Atomic Number and Mass Number of Chlorine**:
- The atomic number of chlorine (Cl) is 17. This means it has 17 protons.
- The mass number of chlorine is typically 35 (for the most common isotope).

3. **Calculate the Number of Neutrons in Chlorine**:
- The number of neutrons can be calculated using the formula:
\[ \text{Number of Neutrons} = \text{Mass Number} - \text{Atomic Number} \]
- For chlorine:
\[ \text{Number of Neutrons} = 35 - 17 = 18 \]

4. **Analyze the Chloride Ion (Cl⁻)**:
- A chloride ion is formed when a chlorine atom gains an electron.
- The atomic number remains the same (17 protons) because the number of protons does not change when an ion is formed.
- The mass number also remains the same (35) because it is determined by the number of protons and neutrons.

5. **Calculate the Number of Neutrons in Chloride Ion**:
- The number of neutrons in the chloride ion is the same as in the chlorine atom:
\[ \text{Number of Neutrons} = 35 - 17 = 18 \]

6. **Determine the Number of Electrons in Chlorine and Chloride Ion**:
- In a neutral chlorine atom, the number of electrons equals the number of protons, which is 17.
- In the chloride ion (Cl⁻), one additional electron is added, making the total number of electrons 18.

7. **Conclusion**:
- The number of protons in both Cl and Cl⁻ is 17.
- The number of neutrons in both Cl and Cl⁻ is 18.
- The only difference is in the number of electrons (17 in Cl and 18 in Cl⁻).

### Final Answer:
The number of protons and neutrons is the same in both the chlorine atom and the chloride ion.