A mixture of two solids is generally _____while a mixture of any number of gases is _______

Explanation

To answer the question, we need to understand the concepts of homogeneous and heterogeneous mixtures.

1. **Understanding Mixtures**: Mixtures are combinations of two or more substances where each substance retains its own properties. They can be classified as homogeneous or heterogeneous.

2. **Mixture of Two Solids**: When we mix two solids, the resulting mixture is generally heterogeneous. This means that the components are not uniformly distributed, and you can often see the individual parts. For example, if you mix sand and salt, you can see the grains of sand and salt separately.

3. **Mixture of Gases**: In contrast, when we mix gases, the mixture is generally homogeneous. This means that the gases are uniformly distributed throughout the mixture, and it is difficult to distinguish one gas from another. For instance, when you mix oxygen and nitrogen, the resulting air is a homogeneous mixture.

4. **Conclusion**: Therefore, we can conclude that a mixture of two solids is generally heterogeneous, while a mixture of any number of gases is homogeneous.

**Final Answer**: A mixture of two solids is generally **heterogeneous** while a mixture of any number of gases is **homogeneous**.

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