Final answer:
The nonvacuum condition has the highest pressure compared to the various degrees of vacuum conditions listed. Pressure is generated by the motion of gas particles and is influenced by temperature. Fluids at room temperature include air, mercury, and water.
Step-by-step explanation:
Among the given options, nonvacuum has the highest pressure because it is representative of normal atmospheric conditions, where there is no vacuum. A high-vacuum environment has a very low pressure close to a perfect vacuum, a low-vacuum has slightly higher pressure but still much lower than atmospheric conditions, and a medium-vacuum is in between, with higher pressure than a high-vacuum but lower than nonvacuum.
Pressure is defined as the force exerted per unit area. Gases create pressure on an object or container by the constant motion and collisions of gas particles against the surfaces they encounter. If gas particles suddenly stopped moving, the pressure would drop to zero. Temperature directly affects pressure; as temperature increases, the energy of gas particles increases, leading to more frequent and forceful collisions and therefore higher pressure.
In review, substances that are fluids at room temperature include air, mercury, and water, but not glass. Gases are easier to compress than liquids and solids due to the larger amount of space between their particles. At high pressures, the actual volume of gas particles becomes significant, affecting the behavior of gases.