How do you verify experimentally that the gases are highly compressible as compared to liquids and solids?

Prove that the gases are highly compressible than liquids and solids.

How do you identify pellagra?

How do you prove the Fermentation?

How do you verify experimentally that the current carrying conductor experiences a force when it is kept in magnetic field?

How do you measure rainfall?

How can you prove experimentally about evaporation and condensation?

How do you prepare polyester?

How do you prove experimentally the ratio V//I is a constant for a given conductor ?