Particle size of colloidal solution is between 1 and 1000nm. The particle size of the substance P is 200nm that lies between the above range. So it will be colloidal solution.

Particle Size and Solution Nature

The particle size of a substance in a solution plays a significant role in determining the nature of the solution. In this case, the particle size of substance 'P' present in water is 200 nm. Let's explore the expected nature of the solution in detail.

1. Introduction
When a substance is dissolved in a liquid, it forms a solution. The size of particles in a solution can vary, ranging from individual atoms or ions to larger particles. The nature of the solution depends on the particle size of the dissolved substance.

2. Nanoparticles
In this case, the particle size of substance 'P' is 200 nm. Nanoparticles are particles that have dimensions in the range of 1-100 nm. At this size range, substances often exhibit unique properties due to their high surface area-to-volume ratio. Nanoparticles can have different behaviors and interactions compared to bulk materials.

3. Colloidal Solution
A colloidal solution, also known as a colloid, is a type of solution in which the particle size of the dissolved substance is between 1-1000 nm. Since the particle size of substance 'P' is 200 nm, it falls within this range. Therefore, the expected nature of the solution is a colloidal solution.

4. Characteristics of Colloidal Solutions
Colloidal solutions have several distinct characteristics due to their particle size:

- Opacity: Colloidal solutions are often opaque or translucent due to the scattering of light by the particles.
- Tyndall Effect: When a beam of light passes through a colloidal solution, it becomes visible as a cone of light due to the scattering of light by the particles.
- Brownian Motion: The particles in a colloidal solution exhibit random motion known as Brownian motion due to collisions with the surrounding solvent molecules.
- Stability: Colloidal solutions can be stable or unstable depending on factors such as particle charge, solvent properties, and presence of stabilizing agents.

5. Applications of Colloidal Solutions
Colloidal solutions have various applications in different fields, including:

- Medicine: Colloidal silver is used as an antimicrobial agent in wound dressings.
- Food Industry: Colloids are commonly used in food products such as mayonnaise, milk, and ice cream to enhance texture and stability.
- Environmental Science: Colloidal particles play a crucial role in the transport and fate of pollutants in natural systems.

Conclusion
In conclusion, based on the particle size of substance 'P' being 200 nm, the expected nature of the solution is a colloidal solution. Colloidal solutions have unique properties and behaviors, which make them useful in various applications across different fields.