#electronicconfiguration#Chemistry#csir#ipe exam#set#easytricksinchemistry

Core Concepts of Electronic Configuration Shells and Subshells: Electrons occupy principal energy levels (shells 1, 2, 3...) which are further divided into subshells labeled s, p, d, and f. Orbital Capacity: Each subshell contains a specific number of orbitals, with each orbital holding a maximum of two electrons. s subshell: 1 orbital (2 electrons max). p subshell: 3 orbitals (6 electrons max). d subshell: 5 orbitals (10 electrons max). f subshell: 7 orbitals (14 electrons max). Governing Principles: Aufbau Principle: Electrons fill lower-energy orbitals first (e.g., 1s before 2s). Pauli Exclusion Principle: No two electrons in an atom can have the same set of four quantum numbers. Hund’s Rule: Electrons will occupy empty orbitals of the same subshell individually before pairing up.  Notation Methods  Standard Notation: Lists every occupied subshell with a superscript indicating the number of electrons (e.g., Oxygen:  1s22s22p41 s squared 2 s squared 2 p to the fourth power ). Noble Gas (Condensed) Notation: Uses the symbol of the previous noble gas in brackets to represent the "core" electrons, followed by the remaining valence electrons (e.g., Calcium: [Ar]  4s24 s squared 4𝑠2 ).