Correct Answer - Option 3 : Porosity
Explanation:
Porosity:
Porosity is defined as the ratio of the volume of the void to the total volume.
\({\rm{n}} = \frac{{{{\rm{V}}_{\rm{v}}}}}{{\rm{V}}}\)
Where,
Vv = Volume of void
V = Total volume
Strength:
The ability of an object to hold heavy weights or not to break or be damaged easily is termed as strength.
Viscosity:
Viscosity is the resistance of a fluid (liquid or gas) to a change in shape or movement of neighbouring portions relative to one another. Viscosity denotes opposition to flow.
Softness:
Those materials which can be easily compressed, cut, bent or scratched are called soft materials.
