A system in which matter may flow in and out, as opposed to a closed system in which matter may not flow in or out.​

Apump contains 0.5 l of air at 203 kpa.you draw back on the piston of the pump, expanding the volume until the pressure reads 50.8 kpa. what is the new volume of the air pump

The number of neutrons is equal to the atomic number minus the atomic mass. a. true b. false

To find the enthalpy of a reaction in the lab, you measured the of the reactants and the change during the reaction.