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.
To find the valency of an element you have to know the number of electrons in the last shell.If it is a metal then the last shell electron ( s ) is its valency or if it is a non metal then the last shell electron ( s ) subtracted from 8 ( since last shell can contain only 8 electrons ) is its valency.And to find the valency of compounds you have to ...