Class 11 Physics Notes Chapter 9 Behaviour of Perfect Gas PDF Class 11 Physics Notes. Chapter 9 Behaviour of Perfect Gas. PDF Download Free. Class 11 Physics Notes Chapter 9: Behaviour of Perfect Gas PDF Downlaod Free Chapter 1 Physics World and Measurement Chapter 2 Kinematics Chapter 3 Law of Motion Chapter 4 Work Energy Power Chapter 5 Motion of System Chapter 6 Gravitation Chapter 7 Properties of Bulk Matter Chapter 8 Thermodynamics Chapter 9 Behavior of Perfect Gas Chapter 10 Oscillations and Waves