Question -
Answer -
(a) The difference in the characteristics of the three states of matter.
| Characteristics | Solid | Liquid | Gas |
| Shape | Fixed shape | No Fixed shape | No Fixed shape |
| Volume | Fixed volume | Fixed volume | No Fixed volume |
| Intermolecular force | Maximum | Less than solids | Very less |
| Intermolecular space | Very less | More than solids | maximum |
| Rigidity/Fluidity | Rigid/cannot flow | Can flow/not rigid | Can flow/not rigid |
| Compressibility | negligible | compressible | Highly compressible |
(b) (i) Rigidity: It is the propensity of a substance to continue to remain in its shape when treated with an external force.
(ii) Compressibility: It is the attribute of the particles to contract its intermolecular space when exposed to an external force thereby escalating its density.
(iii) Fluidity: It is the ability of a substance to flow or move about freely.
(iv) Filling the gas container: The particles in a container take its shape as they randomly vibrate in all possible directions.
(v) Shape: It is the definite structure of an object within an external boundary
(vi) Kinetic energy: Motion allows particles to possess energy which is referred to as kinetic energy. The increasing order of kinetic energy possessed by various states of matter are:
Solids < Liquids < Gases
Mathematically, it can be expressed as K.E =1/2mv2, where ‘m’ is the mass and ‘v’ is the velocity of the particle.
(vii) Density: It is the mass of a unit volume of a substance. It is expressed as:
d = M/V, where ‘d’ is the density, ‘M’ is the mass and ‘V’ is the volume of the substance