Quantum Chemistry

Hopewell Valley Student Podcasting NetworkChemistry ConnectionsQuantum ChemistryEpisode #7  Welcome to Chemistry Connections, my name is Owen Mahan and I am your host for episode #7 called Quantum Chemistry. Today I will be discussing how the effects of quantum mechanics lead to chemistry.Segment 1: Introduction to Quantum MechanicsQuantum mechanics is the mechanism behind the world on the smallest scaleQM acts on the smallest scale, classical mechanics on our scale, relativity on a large scaleQuantum comes from the fact that things are quantizedEnergy, charge, etc can only have certain integer multiples of quantitiesSchrodinger equation (or the wave function) means the values of quantum systems are only probabilisticHeisenberg uncertainty principle means you can’t know everything about a systemPauli exclusion principle says that multiple of the same fermion can’t exist at the same timeFermions have ½ integer spin (electrons, quarks, nucleons by extension, etc) while bosons have whole integer spin (photons, gluons, etc)Segment 2: Quantum Effects on ChemistryBonding/Potential EnergyAll chemical interactions are based on quantum mechanicsBonding occurs because of low potential energy states and electron clouds form because of thatMetallic bonding was used to discover QM via photoelectric effect (Einstein)A solution to the schrodinger equation using Born-Oppenheimer methods is what gives the energy vs nuclear distance graph (as seen on the AP exam)Overlapping is the process by which electron clouds enter a newly favorable state as atoms bondResonance structures are superpositions of electrons within molecules which create multiple simultaneous overlapping cloud structuresOrbitals occur because of spin mechanics as ½ spin particles cannot be indistinguishable, so a max of two electrons (½ and -½ spin respectively) can occupy an orbitalHelium superfluid occurs because He-4 atoms have 0 combined spin so can fall into the same statesNeutron stars (the densest things in the universe) occur because the pressure of fermions not wanting to occupy the same state barely...