Potassium permanganate is purple in color, not orange.

Explanation:
Potassium permanganate is a chemical compound with the formula KMnO4. It is a powerful oxidizing agent and is commonly used in various applications such as water treatment, laboratory experiments, and as a disinfectant.

1. Potassium permanganate is purple in color:
Potassium permanganate crystals or solutions are typically deep purple in color, not orange. The purple color is due to the absorption of certain wavelengths of light by the compound. When dissolved in water, the solution appears pink or purple. This distinct color is often used as an indicator in chemical reactions and titrations.

2. Gases have maximum fluidity and least rigidity:
Gases are the state of matter with the highest degree of fluidity and the least rigidity. Unlike solids and liquids, which have definite volumes and shapes, gases have neither. Gas particles are in constant motion, moving freely and independently from one another. This allows gases to fill the container they are placed in and easily expand or contract in response to changes in temperature and pressure.

3. Solids have negligible kinetic energy (K.E.) of the particles:
Solids have particles that are closely packed and have strong intermolecular forces of attraction. As a result, the particles in solids have very little kinetic energy. They vibrate in fixed positions and do not have the freedom of movement that gases and liquids do. The kinetic energy of particles in solids is negligible compared to the kinetic energy of particles in gases or liquids.

4. Inter-particle attraction depends on the physical state of the matter:
The inter-particle attraction refers to the forces that hold particles together in a substance. The strength of these forces depends on the physical state of matter. In solids, the inter-particle attractions are strong, resulting in a fixed shape and volume. In liquids, the inter-particle forces are weaker, allowing the particles to move past each other, giving liquids their ability to flow and take the shape of their container. In gases, the inter-particle forces are very weak, and the particles move independently of each other with high kinetic energy, allowing gases to expand and fill the available space.

In conclusion, the incorrect statement is option A, as potassium permanganate is purple in color, not orange.