Which is not true about Ideal gas
Interaction between atom or molecule is neglected
  


True. In an ideal gas the gas particles are unaware of each other's existence. 


  
  The transformation to liquid or solid is observed under appropriate condition
  


False. As mentioned in the answer to (1), the particles don't sense each other. Since there are no attractive interactions there is nothing to prevent the gas particles from flying apart, there is nothing to encourage association with other particles. This can of course be a bad assumption in reality, particularly if the gas is highly compressed, but you should not be applying the ideal gas law under such conditions anyway!


  
  The volume of constituent atom or molecule is neglected
  


True. This is a central tenet in the definition of an ideal gas. A correction for a definite particle volume is included in other gas laws, such as van der Waals'. 


  
  The compressibility, PV/RT is independent of pressure
  


True. This follows directly from the definition, $PV=nRT$