International General Certificate of Secondary Education (IGCSE) Chemistry Practice Exam

What does the charge of an electron represent in an electrochemical reaction?

1. A positive charge

2. A negative charge

3. A neutral charge

4. A variable charge

The correct answer is: A negative charge

In an electrochemical reaction, the charge of an electron is fundamentally negative. This negative charge indicates that electrons are subatomic particles that carry this specific charge, which plays a crucial role in the flow of electric current. When electrodes are involved in electrochemical processes, such as in electrolysis or in galvanic cells, it is the movement of these negatively charged electrons that facilitates the transfer of energy and the chemical reactions taking place. The importance of the negative charge is evident in various applications, including how it influences the direction of electron flow: electrons are attracted to positive terminals and repelled by negative terminals. This property is essential for understanding how batteries operate, how corrosion occurs, and how electrochemical cells generate electricity. Recognizing that electrons have a negative charge provides foundational knowledge in the study of electrochemistry and its practical applications in technology and industry.