When does an atom acquire an overall positive charge?

Options

A. When it gains protons
B. When it loses neutrons
C. When it gains electrons
D. When it loses electrons

Answer

To determine when an atom acquires an overall positive charge, we need to understand the roles of protons, neutrons, and electrons in an atom.

### Step-by-Step Solution:

1. **Understanding Atomic Structure**:
- An atom consists of protons, neutrons, and electrons. Protons are positively charged, neutrons are neutral (no charge), and electrons are negatively charged.

2. **Charge of Protons and Electrons**:
- Each proton carries a charge of +1e, while each electron carries a charge of -1e. Neutrons do not contribute to the charge of the atom.

3. **Movement of Particles**:
- In an atom, protons and neutrons are located in the nucleus and do not move. Electrons, however, are found in the electron cloud surrounding the nucleus and can move between atoms.

4. **Conditions for Positive Charge**:
- An atom is neutral when the number of protons equals the number of electrons. If an atom loses electrons, it will have more protons than electrons, resulting in a net positive charge.

5. **Evaluating Options**:
- **Gains Protons**: Not possible, as protons do not move.
- **Loses Neutrons**: Neutrons are neutral; losing them does not affect the charge.
- **Gains Electrons**: This would increase the negative charge, not create a positive charge.
- **Loses Electrons**: This results in a deficiency of negative charge, leading to an overall positive charge.

6. **Conclusion**:
- An atom acquires an overall positive charge when it **loses electrons**. Therefore, the correct answer is **option 4**.