Fill in the blank: Unlike solids, both liquids and gases are classified as __________ because their particles are not in fixed positions and can flow.

According to the particle model, when a gas is compressed using a syringe, what specifically is changing at the molecular level?

True or False: According to the kinetic molecular theory, the pressure measured in a gas-filled container is primarily the result of gas particles colliding with each other.

In the context of fluid behavior, what distinguishes the expansion of a gas from that of a liquid when transferred from a small sealed flask to a larger vacuum-sealed one?

In the combined gas law equation, $\frac{P_1 V_1}{T_1} = \frac{P_2 V_2}{T_2}$, what property of the gas system is assumed to remain constant?