Suspensions are :

Options

A. Visible to naked eye
B. Not visible by any means
C. Invisible under electron microscope
D. Invisible through microscope

Answer

To determine what suspensions are, let's analyze the characteristics of suspensions step by step.

### Step-by-Step Solution:

1. **Definition of Suspension**:
- A suspension is defined as a heterogeneous mixture where solid particles are dispersed in a liquid or gas.

**Hint**: Remember that a heterogeneous mixture has distinct phases or components that can be identified.

2. **Visibility of Particles**:
- The particles in a suspension are large enough to be seen with the naked eye. This means that when you look at a suspension, you can observe the solid particles floating in the liquid.

**Hint**: Think about examples like muddy water or chalk mixed with water, where you can see the particles.

3. **Light Scattering**:
- When light passes through a suspension, the particles scatter the light, making the path of the light beam visible. This phenomenon is known as the Tyndall effect.

**Hint**: Consider how a beam of light looks when it passes through fog or a dusty room; this is similar to what happens in a suspension.

4. **Behavior of Particles Over Time**:
- If a suspension is left undisturbed, the solid particles will eventually settle at the bottom due to gravity. This settling indicates that the mixture is not a solution.

**Hint**: Think about what happens when you leave a salad dressing (oil and vinegar) undisturbed; the heavier components settle.

5. **Examples of Suspensions**:
- Common examples of suspensions include muddy water and a mixture of chalk and water. These examples illustrate the characteristics of suspensions well.

**Hint**: Try to visualize or recall other examples of suspensions that you might have encountered in daily life.

6. **Evaluating Options**:
- Now, let's evaluate the given options:
- **Option 1**: Visible to the naked eye (Correct)
- **Option 2**: Not visible by any means (Incorrect)
- **Option 3**: Invisible under an electron microscope (Incorrect)
- **Option 4**: Invisible through a microscope (Incorrect)

**Hint**: When evaluating options, always refer back to the definition and characteristics of suspensions.

### Conclusion:
The correct answer is that suspensions are visible to the naked eye.