Flow can be described in units of all the following EXCEPT?

Flow is typically measured in terms of how much fluid moves over a certain period of time, which is where the units of volume, mass, and velocity come into play. Volume flow rate is often expressed in units such as liters per minute or gallons per hour, emphasizing how much volume of fluid passes through a given point in a specified time frame. Mass flow rate, on the other hand, relates to the mass of fluid that moves through a point over time, which can be expressed in kilograms per second or pounds per hour.

Velocity as a measure is related to how fast the fluid is moving, often measured in meters per second or feet per second, describing the speed at which the fluid flows.

Density, however, is not a measure of flow itself; rather, it describes the mass of a substance per unit volume. While density can influence flow rates (for example, through its impact on the performance of certain systems), it does not describe the flow in terms of how much fluid passes a point over time. Therefore, density does not belong among the typical units used to describe flow.