A positive ion forms when an atom ______.

• A. gains one or more electrons
• B. loses one or more neutrons
• C. loses one or more electrons
• D. gains one or more protons

Answer: (C)

Verified step by step guidance

1. Understand that ions are charged particles formed when atoms gain or lose electrons.
2. Recall that electrons carry a negative charge, so gaining electrons makes an atom negatively charged (an anion).
3. Recognize that losing electrons removes negative charge, resulting in a positively charged ion (a cation).
4. Note that protons and neutrons are located in the nucleus and do not change during ion formation; changing protons would change the element itself.
5. Therefore, a positive ion forms when an atom loses one or more electrons.