Comment upon the following: Rigidity, compressibility, fluidity, filling a gas container, shape, kinetic energy, and density.

(N/A) $Rigidity$: The property by which an object retains its shape and size is called rigidity. Solids are rigid, whereas liquids and gases are not.
$Compressibility$: This is the property due to which a substance can be compressed, meaning its volume can be decreased. Gases are highly compressible, whereas solids and liquids are generally considered incompressible.
$Fluidity$: The tendency of a substance to flow is called fluidity. Gases and liquids are fluids, while solids are not.
$Filling \text{ } a \text{ } gas \text{ } container$: $A$ large volume of gas can be filled into a small container by compressing it under very high pressure. This is possible due to the high compressibility of gases.
$Shape$: The property of having a definite geometry is called the shape of a substance. Solids have a definite shape, whereas liquids and gases take the shape of the container.
$Kinetic \text{ } energy$: The energy possessed by moving particles or molecules is called kinetic energy. On increasing the temperature, the kinetic energy of molecules increases. Gas molecules possess the highest kinetic energy.
$Density$: The mass per unit volume of a substance is called density. Density = $\frac{\text{Mass}}{\text{Volume}}$.