Basic Terms (Cells, Batteries, Current, etc.)

What is an electric cell?

A device that converts chemical energy → electrical energy through a redox reaction.

What is a battery?

Two or more electric cells connected together.

What is an electrode?

A solid conductor where oxidation or reduction happens.

What is an electrolyte?

A solution or paste that conducts ions.

What is potential difference?

The energy per charge between two points; measured in volts.

What is voltage?

Another term for potential difference.

What is electric current?

The flow of electric charge (electrons in wires, ions in solutions).

What is an ampere?

Unit of electric current: 1 coulomb per second.

What is a coulomb?

Unit of electric charge.

What is a primary cell?

A cell that cannot be recharged. The reaction is non-reversible.

What is a secondary cell?

A rechargeable cell. Reaction can be reversed.

What is a fuel cell?

A cell that uses continuous external fuel (e.g., H₂ + O₂) to produce electricity.

: How to identify oxidation vs reduction in a cell?

Oxidation: electrons lost, oxidation number increases

Reduction: electrons gained, oxidation number decreases

Oxidation happens at the anode; reduction at the cathode