What is an electrochemical cell or galvanic cell?

Explanation

### Step-by-Step Solution

1. **Definition of Electrochemical Cell**: An electrochemical cell, also known as a galvanic cell, is a device that converts chemical energy into electrical energy.

2. **Spontaneous Chemical Reactions**: The process that occurs in a galvanic cell is based on spontaneous chemical reactions. This means that the reactions occur naturally without the need for external energy input, and they have a negative Gibbs free energy change (ΔG < 0).

3. **Components of the Cell**: A galvanic cell consists of two electrodes: the anode and the cathode. The anode is where oxidation occurs, and the cathode is where reduction takes place.

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