When silver tarnishes, which chemical reaction occurs on its surface?

• A. Silver reacts with sulfur compounds in the air to form silver sulfide (Ag2S).
• B. Silver reacts with carbon dioxide to form silver carbonate (Ag2CO3).
• C. Silver reacts with nitrogen to form silver nitride (Ag3N).
• D. Silver reacts with oxygen to form silver oxide (Ag2O).

Answer: (A)

Verified step by step guidance

1. Understand that tarnishing of silver is a chemical process where silver reacts with substances in the environment, leading to a visible surface change.
2. Identify common atmospheric compounds that can react with silver. These include oxygen (O2), sulfur compounds (like hydrogen sulfide, H2S), carbon dioxide (CO2), and nitrogen (N2).
3. Recall that silver is particularly prone to reacting with sulfur-containing compounds, which are often present in small amounts in the air, especially in polluted environments.
4. Write the chemical reaction for silver tarnishing: silver (Ag) reacts with sulfur compounds to form silver sulfide (Ag2S), which appears as a dark layer on the surface.
5. Recognize that other reactions such as silver with oxygen, carbon dioxide, or nitrogen are either less common or do not produce the typical tarnish seen on silver objects.