Explain why viruses cannot be seen using a microscope?

Explanation

### Step-by-Step Solution:

1. **Understanding Visibility**: Viruses are not visible to the naked eye. They are extremely small and require special equipment to be observed.

2. **Size Comparison**: The size of viruses is typically in the range of nanometers (nm), which is 1 nm = 10^-9 meters. In contrast, the smallest objects that can be seen with a standard compound microscope are in the micrometer (µm) range, which is 1 µm = 10^-6 meters.

3. **Microscope Limitations**: A compound microscope can generally observe objects that are about 0.1 mm (100 µm) in size. This means it can see cells and tissues, which are micrometer-sized objects.

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