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.
A work of art, artwork, art piece, piece of art or art object is an aesthetic physical item or artistic creation. Apart from work of art, which may be used of any work regarded as art in its widest sense, including works from literature and music, these terms apply principally to tangible, portable forms of visual art: 1  An example of fine art, such as a painting or sculpture. An object that has been designed specifically for its aesthetic appeal, such as a piece of jewelry. An object that has been designed for aesthetic appeal as well as functional purpose, as in interior design and much folk art.