Requirements management - Overview. 1  The purpose of requirements management is to ensure that an organization documents, verifies, and meets the needs and expectations of its customers and internal or external stakeholders. Requirements management begins with the analysis and elicitation of the objectives and constraints of the organization.
The highest occupied electron shell is called the valence shell, and the electrons occupying this shell are called valence electrons. The chemical properties of the elements reflect their electron configurations. For example, helium, neon and argon are exceptionally stable and unreactive monoatomic gases.
1 For inner transition elements the valence electrons are those in the s sub-shell of the outermost energy shell the d sub-shell of the next to outermost energy shell, and the f sub-shell of the energy shell two levels below the outermost shell.