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.
share. 1  a part or portion that belongs or is allotted to an individual, or the part contributed by an individual. 2  a just, due, reasonable, or full part or quota: to do one's share of work. 3  any of the parts or portions into which the ownership of a piece of property is divided.