Measuring instantaneous rates is the most direct way of determining the rate law of a reaction, but it is not always convenient, and it may not be possible to do so with precision.
piece (pÄs) n. 1. A thing considered as a unit or an element of a larger thing, quantity, or class; a portion: a piece of string. 2. A portion or part that has been separated from a whole: a piece of pie. 3. An object that is one member of a group or class: a piece of furniture.
collective. adjective. 1  Assembled into or viewed as a whole. 2  Of, relating to, characteristic of, or made by a number of people acting as a group: a collective decision.he definition of collective is a group of people working together toward a common goal or in an organization. An example of collective used as an adjective is a collective art project, a group of artists working together on a mural.