Argon has a normal boiling and freezing points of 87.3 K and 83.8 K, respectively. The triple point of argon occurs at 83.8K at 0.68 atm. What physical change can be observed- if any- when the temperature of an argon sample is increased from 85K to 90K at a constant pressure of 0.46 atm? No physical change occurs- the sample is gas and stays gas liquid to gas no physical change occurs- the sample is liquid and stays liquid solid to gas solid to liquid