What is the free energy criterion for a process to occur spontaneously?

Explanation

To determine the free energy criterion for a process to occur spontaneously, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Spontaneity**:
- A spontaneous process is one that occurs without needing to be driven by an external force. This can be indicated by changes in entropy (ΔS) and free energy (ΔG).

2. **Entropy Change (ΔS)**:
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