Which of the following correctly describes the pressure, volume, temperature, and number of particles of a gas? Click the answer you think is right. Temperature is constant for a particular gas. The pressure can be used to identify the gas. If one changes, at least one of the others will also change. These properties only apply to some gases. 

OPTION 3: If one changes, at least one of the others will also change.

Step-by-step explanation

Option 1 is WRONG because the temperature can never be constant. Note that the temperature of different gases varies and this property depends on the conditions under which the certain gas is subjected.

Option 2 is WRONG because the pressure alone is insufficient for us to know the identity of the gas. In order to know the identity of the gas, we also need to know the temperature, the volume and the number of moles.

Option 3 is CORRECT because based from the ideal gas equation of state, the pressure, volume, temperature, and the number of moles of a gas are all interconnected and dependent on each other using the formula PV = nRT. Therefore, if one variable changes, it is expected that at least one or more of the other variables changes. For example if the pressure increases, the volume decreases since it is inversely proportional to pressure while the number of moles and the temperature is expected to increase since they are directly proportional to pressure.

Option 4 is WRONG because all gases must have its pressure, temperature, volume and number of moles based from the ideal gas law. The value for these properties depend on the condition which the gases are subjected to.

Therefore the answer is OPTION 3: If one changes, at least one of the others will also change.