When a Cl atom gains an electron, it gets a charge of

Options

A. `-1`
B. `+1`
C. 0
D. `+2`

Explanation

To determine the charge of a chlorine atom when it gains an electron, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Initial State of Chlorine Atom**:
- A chlorine atom (Cl) has an atomic number of 17, which means it has 17 protons and, in its neutral state, 17 electrons.

2. **Understand the Concept of Electron Gain**:
- When an atom gains an electron, it acquires a negative charge. This is because electrons carry a negative charge.

3. **Calculate the Charge After Gaining an Electron**:
- If a chlorine atom gains one electron, it will now have 18 electrons (17 original + 1 gained).
- The number of protons remains the same at 17.

4. **Determine the Overall Charge**:
- The overall charge of the atom can be calculated by subtracting the number of protons from the number of electrons:
- Charge = Number of Electrons - Number of Protons
- Charge = 18 (electrons) - 17 (protons) = +1
- Since it has gained an electron, the charge becomes negative:
- Therefore, the charge of the chlorine atom after gaining an electron is -1.

5. **Conclusion**:
- When a chlorine atom gains an electron, it gets a charge of -1.

### Final Answer:
When a Cl atom gains an electron, it gets a charge of -1.