Definition A tree is a collection of nodes. The collection can be empty: otherwise, a tree consists of (1) a distinguished node r, called the root; (2)and zero or more nonempty(sub)trees T1,., Tk, each of whose roots are connected by a directed edge from r Note:
Functional groups The structural features that make it possible to classify compounds by reactivity are called functional groups. A functional group is a part of a larger molecule and is composed of an atom or a group of atoms that have a characteristic chemical behavior. The Chemistry of every organic molecules
Explain or explore something, (e. g, process of make a machine, the causes of a natural or ocial phenomenon, the planning of a project, or a solution of a problem) Description mainly deal with appearance and feelings, and narration with events and experiences, unlike the two, the exposition mainly deals with relationships as well as processes
