Statement I If thermal energy is stronger than intermolecular forces, the substance prefers to be in gaseous state. When thermal (kinetic) energy of molecules exceeds the intermolecular attractive forces, the molecules move freely, far apart - this is the gaseous state. Statement I is correct. Statement II At constant temperature, the density of an ideal gas is proportional to its pressure. From the ideal gas law: PV=nRT or P=
n
V
RT Now,
n
V
=
ρ
M
, where ρ is density and M is molar mass. Thus, P=
ρ
M
RT⇒ρ=
PM
RT
At constant T and M : ρ∝P Statement II is also correct.
