Quantum Theory

• Quantum or Wave Mechanics - a theory describing wave properties of electrons.
• The TWO electron properties:

  • A moving PARTICLE with an EXACT location
  • A WAVE that is DIFFUSED
• Although Schrodinger disagreed with an electron being a particle due to being unable to find it's accurate location, he instead described it as a wave in order to find the probability of an electron in a certain place.
• In Schrodinger's Theory, the GROUND state is the LOWEST e- wave pattern
• In Schrodinger's Theory, when the wave shape has a large amplitude/node, the probability of an electron is at a certain location in space or the e- density.
• The electron density is around the nucleus
• Darker region around the nucleus = Higher density and e- probability
• In the Hydrogen ground state, the MAX probability density is 0.529 Angstroms = according to Bohr's prediction, n = 1.
• Shrondingers Theory says that electrons spend MOST of their time at the distance, meaning they may relocate at anytime.
• Bohr's Theory says that electrons spend ALL of their at the distance, meaning that they reside there.
• The wave function, in Schrodinger's Theory is use to provide information about the probability of finding the electron in a given region of a space around the nucleus.
• Wave functions are like water waves, having crests and troughs, but they are different graph-wise.
• Wave functions can be called orbitals.
• Orbitals represent a region of space around the nucleus in which there is a high probability an electron can be found.
• According to Schrodinger's Theory, electrons are NOT found at a given point, meaning there are INFINITE points around the nucleus and the probability is SMALL.
• The quantum orbitals (n, l, $m_l$) in Schrodinger's Theory represents the number of degenerate orbitals, the orbitals of same energy levels.
• Bohr Model - e- lives/resides in orbits around nucleus.
• Bohr Model - electrons are located at a SPECIFIC distance.
• Bohr Model - Defined by 1 quantum number for the ENERGY and ORBIT of the electron.
• Bohr Model - Describes e- as a particle, moving in a circular path.
• Schrodinger Model - e- is located/possibly found in orbitals.
• Schrodinger Model - the orbitals have various shapes defined by the 3 quantum numbers: n, l, $m_l$
• Schrodinger Model - e- is a wave.
• BOTH the Schrodinger and Bohr Model allows the quantization of e- energy.
• Bohr Model - moving between orbits requires:

  • Energy radiation
  • Energy absorption
  • $∆E =$$E_F - E_I$ or $E =$$hv =$$(hv)/v$(line spectrum)
• Schrodinger Model - A change in e-s =a change in wave function
• Schrodinger Model - New function = New shape
• Schrodinger Model - NEW location = NEW orbital; A move between orbitals
• ISSUE # 1: How does an electron move from orbital to another WITHOUT being between the TWO?

  Moving between orbits from a change in wave function
• ISSUE #2: How does an electron stay in orbit WITHOUT being in a nucleus spiral?

  ZERO probability of e- being in the nucleus
• ISSUE #3??: Localization of e- to an exact location 


  predicts probable locations