Which of the following atoms could form an anion with -2 charge?

Options

A. Se
B. Po
C. Cl
D. H

Explanation

To determine which of the given atoms can form an anion with a -2 charge, we will analyze each atom based on its position in the periodic table and its ability to gain electrons.

### Step-by-Step Solution:

1. **Identify the Atoms**: The atoms in question are Selenium (Se), Polonium (Po), Chlorine (Cl), and Hydrogen (H).

2. **Determine the Group of Each Atom**:
- **Selenium (Se)**: This element is in Group 16 (the oxygen family).
- **Polonium (Po)**: This element is also in Group 16 (the oxygen family).
- **Chlorine (Cl)**: This element is in Group 17 (the halogens).
- **Hydrogen (H)**: This element is in Group 1.

3. **Understand the Electron Configuration**:
- **Selenium (Se)**: The electron configuration is [Ar] 4s² 3d¹⁰ 4p⁴. It needs to gain 2 electrons to achieve a stable octet, forming Se²⁻.
- **Polonium (Po)**: The electron configuration is [Xe] 6s² 4f¹⁴ 5d¹⁰ 6p⁴. Like selenium, it can gain 2 electrons to form Po²⁻.
- **Chlorine (Cl)**: The electron configuration is [Ne] 3s² 3p⁵. Chlorine typically forms a -1 charge (Cl⁻) by gaining 1 electron.
- **Hydrogen (H)**: The electron configuration is 1s¹. Hydrogen can either lose an electron to form H⁺ or gain one to form H⁻, but it does not form a -2 charge.

4. **Conclusion**:
- The elements that can form anions with a -2 charge are Selenium (Se) and Polonium (Po). Chlorine can only form a -1 charge, and Hydrogen does not form a -2 charge.

### Final Answer:
The atoms that could form an anion with a -2 charge are **Selenium (Se) and Polonium (Po)**.

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