How many electrons in the `Cl^(-)` ion have value of m=0?

Explanation

To determine how many electrons in the `Cl^(-)` ion have the magnetic quantum number (m) equal to 0, we will follow these steps:

### Step 1: Determine the Electron Configuration of Cl^(-)
Chlorine (Cl) has an atomic number of 17, meaning it has 17 electrons. The `Cl^(-)` ion has one additional electron, bringing the total to 18 electrons. The electron configuration for Cl^(-) is:
- 1s²
- 2s²
- 2p⁶
- 3s²
...