Define electronic configuration and valency

Dear student. Electronic configurationis the arrangement of electrons in the atomic or molecular orbitals of atoms or molecules. We know that, neutrons and protons are present in the nucleus which is present at the center of an atom, and electrons are present around the nucleus. Thus, it is this arrangement of electrons, into different shells and sub-shells is called electronic configuration. Example: Atomic number of oxygen is 8 and its electronic configuration is: 2,6.Valency is defined as number of electrons present in outermost orbitals of atom of element. For example : Valency of Nitrogen is 3 because outermost orbital contain 3 electron. Regards