can be liquefied if its temperature is more than critical temperature

can be liquefied if its pressure is more than critical pressure

cannot be liquefied at any pressure and temperature

can be liquefied ,if its temperature is more than Boyle’s temperature

the change in internal energy in a constant pressure process from temperature `The_1 to The_2` is equal to ``nC_v(T_2-T_1)` where `c_v` is the molar heat capacity at constant volume and n is the number of moles of the gas

the change in internal energy of the gas and the work done by the gas are equal in magnitude in an adiabatic process

the internal energy does not change in an isothermal process

no heat is added or removed in an adiabatic process