QUANTUM MECHANICAL MODEL  Determines the allowed energies an electron can have  Determines how likely it is to find the electron in various locations

QUANTUM MECHANICAL MODEL  CLOUD or ORBITAL MODEL PROPABILITY OF FINDING AN ELECTRON WITHIN A CERTAIN VOLUME OF SPACE AROUND THE NUCLEUS (orbital) High density =high propability Low density =low probability Shape of the cloud represents a 90% probability

QUANTUM MECHANICAL MODEL GENERAL PLAN  PRINCIPLE ENERGY LEVEL (n) ENERGY SUBLEVELS (l) indicate the shape of orbital which contains  ATOMIC ORBITALS (m) Orientation of orbital around nucleus (Electrons found here) Number of electrons per atomic orbital =2

QUANTUM MECHANICAL MODEL principle energy levels  PRINCIPLE ENERGY LEVELS LABELED BY PRINCIPLE QUANTUM NUMBERS (n) n=1,2,3,4,5,6,etc.  As n> the electrons energy > and distance from nucleus >  Can be called a shell  Within a given energy level there may be several sublevels that have orbitals

QUANTUM MECHANICAL MODEL energy sublevels  ENERGY SUBLEVEL (l) Each energy sublevel corresponds to orbitals of different shapes where the electron is likely to be found Sublevel could be called a subshell

QUANTUM MECHANICAL MODEL energy sublevels  ENERGY SUBLEVEL(l) (Orbital shapes)  Labeled by letters s = spherical shape p = dumbbell shape d = clover leaf + f = too complicated

QUANTUM MECHANICAL MODEL atomic orbitals  ATOMIC ORBITAL (m) (Orbital orientation)  THE s SUBLEVEL HAS ONLY ONE ORBITAL, s

QUANTUM MECHANICAL MODEL atomic orbitals  Atomic orbital (orbital orientation)  THE p SUBLEVEL HAS THREE ORBITALS—p x, p y, p z

QUANTUM MECHANICAL MODEL atomic orbitals  Atomic orbital (orbital orientation)  THE d SUBLEVEL HAS 5 ORBITALS– d xy, d xz, d yz, d x2-y2,d z2

QUANTUM MECHANICAL MODEL atomic orbitals  Atomic orbital(orbital orientation)  THE f SUBLEVEL HAS 7 ORBITALS  They are too complicated to show or name

QUANTUM MECHANICAL MODEL electron location  Within each orbital there can be a maximum of 2 electrons  EACH ELECTRON MUST HAVE AN OPPOSITE SPIN- +1/2 or -1/2

QUANTUM MECHANICAL MODEL RELATIONSHIPS  Relationships between Energy levels n=energy level SUBLEVELS n=number OF SUBLEVELS ORBITALS n 2 =number OF ORBITALS PER ENERGY LEVEL ELECTRONS 2n 2 = MAXIMUM NUMBER OF ELECTRONS PER ENERGY LEVEL

QUANTUM MECHANICAL MODEL SUMMARY OrganizationDesignation Principle energy level (shell) Sublevel (subshell) Atomic orbital Spin

Energy Level Subshells or sublevel # of OrbitalsMaximum number of e - s per orbital Total number of e - s per energy level n = 1 n = 2 n = 3 n = 4

QUANTUM MECHANICAL MODEL  Electron configuration The relationship between energy and stability Electrons and nucleus interact to make the most stable arrangment possible (lowest energy) There are three rules for electron configurations

QUANTUM MECHANICAL MODEL  Electron configuration Aufbau princple Electrons occupy the orbitals of lowest energy first

QUANTUM MECHANICAL MODEL  AUFBAU RULE

QUANTUM MECHANICAL MODEL  AUFBAU ORDER FILLING

QUANTUM MECHANICAL MODEL  Electron configuration Pauli exclusion principle One orbital may describe at most 2 electrons To occupy the same orbital, the two electrons must have opposite spins ↑↓

QUANTUM MECHANICAL MODEL  Electron configuration Hunds rule When filling orbitals of equal energy, one electron occupies each orbital until all orbitals contain one electron with the same spin direction

QUANTUM MECHANICAL MODEL  Electron arrangement Orbital notation Electron configuration notation Exceptions Half-filled sublevels are less stable than filled sublevels but more stable than other configurations