GED Science Practice

What is a negatively charged electrode that is the source of electrons in an electrical device called?

1. Cell

2. Cell Membrane

3. Catalyst

4. Cathode

The correct answer is: Cathode

A negatively charged electrode that serves as the source of electrons in an electrical device is known as a cathode. In electrochemical cells or during electrolysis, the cathode is where reduction reactions occur, meaning that electrons are gained by the species present at this electrode. This is fundamental to the operation of devices like batteries, where the cathode attracts positive ions and electrons from an external circuit. While the term "cell" refers to the entire system that generates or uses electrical energy and "cell membrane" pertains to biological structures that separate interior environments from their exterior surroundings, they do not specifically refer to the electrode. "Catalyst," on the other hand, denotes a substance that accelerates a chemical reaction without being consumed, but it does not produce electrons nor is it specifically linked to an electrical device's electrode system.