Which of the following could serve as an electrode material?

• A. Graphite
• B. Plastic
• C. Wood
• D. Glass

Answer: (A)

An electrode must conduct electricity and remain chemically stable in the reacting environment. Graphite fits that role because it’s a form of carbon with a structure that lets electrons flow easily, so it conducts well and is relatively inert in many electrolytes, making it a reliable electrode material. Plastic, wood, and glass, on the other hand, are insulators—they don’t conduct electricity well—so they wouldn’t allow the current to pass through a circuit and can’t function as electrodes. That’s why graphite is the suitable choice.