5.3 Electron Configuration Year 4 PDF

5.3 Electron configuration Year 4 Electron configuration:  It’s the arrangement of electrons in an atom, using orbitals similar to hydrogen’s.  The most stable, lowest-energy arrangement of the electrons is called the element’s ground-state electron configurati...

5.3 Electron configuration Year 4 Electron configuration:  It’s the arrangement of electrons in an atom, using orbitals similar to hydrogen’s.  The most stable, lowest-energy arrangement of the electrons is called the element’s ground-state electron configuration  It follows certain rules: Aufbau principle, Pauli exclusion principle and Hund’s rule. Aufbau principle: Aufbau rule, states that in the ground state of an atom or ion, electrons fill atomic orbitals of the lowest available energy levels before occupying higher levels. Pauli exclusion principle:  The maximum of 2 electrons occupy each orbital, with opposite spin state.  Maximum number of electrons occupying an orbit is: 2.  Maximum number of electrons occupying an energy level is: 2n2  You cannot find 2 electrons in an atom having the same set of quantum numbers, each electron has a different set 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.  Electron configuration notation (Aufbau diagram) Electron orbital diagram configuration noble gas notation Electron configuration notation: The electron configuration notation designates the principal energy level and energy sublevel associated with each of the atom’s orbitals and includes a superscript representing the number of electrons in the orbital. Practice:  Write the E.C of the following elements: 1) Y 2) Ge 3) Br Exception to Aufbau principle:  The stability of d sublevel increases if it’s half filled or saturated with electrons. Orbital diagram: electrons in orbitals can be represented by arrows in boxes. Each box is labeled with the principal quantum number and sublevel associated with the orbital. Practice:  Write the orbital diagram of the following elements: 1) Y 2) Ge 3) Br Noble gas notation: Practice:  Write the noble gas notationof the following elements: 1) Y 2) Ge 3) Br P: 160 Electron dot structure and valence electrons:  Valence electrons: are the  Electron dot structure: consists electrons that occupy the of the chemical symbol that outermost shell, they have the represents the nucleus and the highest energy, and they are inner-level electrons responsible for the chemical surrounded by dots properties of elements and representing all of the atom’s bonding. valence electrons. P: 162 P: 162