Which property of a substance is not altered by a physical change?

How many moles of air are there in a human lung with a volume of 2.4 l at stp? explain your answer

If i initially have a gas at a pressure of 12 atm, a volume of 23 liters, and a temperature of 200 k, and then i raise the pressure to 14 atm and increase the temperature to 300 k, what is the new volume of the gas?

What is the ph of a solution that has a hydrogen ion concentration of 1.0 * 10 -9 m?