Electron configuration
Arrangement of electrons in an atom
3 rules:
Aufbau Principle; Pauli Exclusion Principle; Hund's Rule
Alfbau Principle
Each electron occupies the lowest energy orbital
Pauli Exclusion Principle
Maximum of 2 electrons may occupy a single atomic orbital but only if the electrons have opposite spins
Features of Aufbau Diagram
All orbitals related to an energy sublevel are of equal energy
Multi-electron atom, energy sub levels within principal energy level have different energies
In order of increasing energy, sequence of energy sub levels within a principal energy level is s,
Aufbau Diagram can be used?
To write correct ground-state electron configurations for all elements up to & including Vanadium, atomic number 23
Transition metals like copper & chromium
Do not follow Aufbau Diagram because of increases stability of half-filled & filled seats of s & d orbitals
Wolfgang Pauli
Observed atoms in excited states
Atomic Orbital containing paired electrons with opposite spins written?
????
Hund's Rule
Single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbitals
Represent atom's electron configuration
Orbital Diagram
Empty box
Unoccupied orbital
Box containing ??
Orbital with 1 electron
Box containing ????
Filled orbital
Box labeled with?
Principal quantum number & sublevel associated with orbital
Electron configuration notation
Shorthand method for describing arrangement of electrons in an element's atoms
Method designates what?
Principle energy & energy sublevel representing number of electrons in orbital
Noble-gas notation
Method of representing electron configurations of noble gases using bracketed symbols
Valence Electrons
Electrons in the atom's outermost orbitals - generally those orbitals associated with the atom's highest principal energy level
Determine the chemical properties of an element
Electron configurations represented by?
Orbital Diagrams, Electron Configuration Notation, Electron-Dot Structures
Electron-Dot Structure
Consist of element's symbol which represents the atomic nucleus & inner-level electrons, surrounded by dots representing the atom's valence electrons