# Comment upon the following: rigidity, compressibility, fluidity, filling a gas container, shape, kinetic energy, and density. Also, please compare these properties with solids, liquids and gases.

Dear Student,

• Rigidity : It is the state in which the particles of a substance are fixed in their positions.
• Compressibility : It is a property by which the volume of a sunstance can be reduced, or a substance can be made compact, by pressing it.
• Fluidity : It is the property by virtue of which, the particles of a molecule move in space. A substance whose particles can move easily is said to be fluid, for example, liquid.
• A gas conatiner can be filled with a gas by compressing the gas, as the particles of a gas have more space between them, and they can be brought closer to each other, by increasing the perssure of the gas.
• Shape of a substance defines the arrangement of constitutent particles, of that substance in space.
• Kinetic energy is the energy of any substance in motion.
• Density : It is the the packing of the constituent particles, in a given volume of the substance. It can also be referred to as thickness of the substance.

Follwoing table provides the comparison between solids, liquids and gases.

 Solid Liquid Gas They are very rigid, as constituent particles are tightly held to each other. They are comparitively less rigid, as the particles can move and are flexible. They take the shape of the container. They are not rigid, as the particles are free to move in space. They are non compressible, due to close packing of the particles. They can be compressed to some extent. They are highly compressible, as large space is present between the particles, adn they can be brought close to each other. They have fixed shape. They take the shape of the container. They also, take the shape of the container. The particles of solids have very less The particles possess some amount of Kinetic energy. The particles are in motion continously, but do not leave the liquid surface. The particles possess very large kinetic energy, as they are continously in motion and move with hihg speeds. The density is high, due to close packing of particles. Density is comparatively lower, than the solids, as particles are not too close to each other. Density is very low, as the number of particles in a given volume is very low.