on the basic of bulk modulus and compressibility which materials are easier to compress
Bulk modulus is the measurement of decrease in volume while increase in pressure.the bulk modulus property of material is related to behaviour of elasticity.
Bulk modulus can also be defined as the relative change in the volume of body produced by unit compressive or tensile strength.
Summary:gases will compress more easily than solids and liquids because there is more gap present in between the gas molecules.