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.
Each shell can contain only a fixed number of electrons: The first shell can hold up to two electrons, the second shell can hold up to eight (2 + 6) electrons, the third shell can hold up to 18 (2 + 6 + 10) and so on.The general formula is that the n th shell can in principle hold up to 2(n2) electrons.he electrons in the outermost occupied shell (or shells) determine the chemical properties of the atom; it is called the valence shell. Each shell consists of one or more subshells, and each subshell consists of one or more atomic orbitals.