In some cases, Ellingham diagrams (graphs) show a bend. What do you refer from it ?

Explanation

### Step-by-Step Solution:

1. **Understanding Ellingham Diagrams**:
- An Ellingham diagram is a graphical representation that shows the relationship between temperature and the stability of compounds, particularly metal oxides and sulfides. It plots the Gibbs free energy change (ΔG) against temperature.

2. **Identifying the Axes**:
- The x-axis of the diagram represents temperature, while the y-axis represents the Gibbs free energy change (ΔG). The lines on the graph correspond to different reactions, typically the formation of metal oxides from their elements.

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