1. The document discusses properties of air and gas laws including Boyle's law, Charles' law, and the combined gas law. 2. Boyle's law states that if temperature is constant, volume and pressure of a gas are inversely related. Charles' law states that if pressure is constant, volume and temperature of a gas are directly related. 3. The combined gas law incorporates both, stating that if volume is constant, pressure and temperature are directly related. Air pressure and how it is measured is also discussed.