Which process leads to the formation of an anion?

• A. An atom shares electrons with another atom.
• B. An atom gains one or more electrons.
• C. An atom undergoes nuclear decay.
• D. An atom loses one or more electrons.

Answer: (B)

Verified step by step guidance

1. Understand that an anion is a negatively charged ion formed when an atom gains electrons.
2. Recall that when an atom gains one or more electrons, it acquires extra negative charge, resulting in an anion.
3. Recognize that sharing electrons (as in covalent bonding) does not create an anion because the electrons are shared, not gained or lost.
4. Note that nuclear decay involves changes in the nucleus and does not directly affect the electron count to form an anion.
5. Understand that losing electrons results in a positively charged ion called a cation, not an anion.