# Quantum Mechanics

Three physicists were instrumental: Heisenberg, De Broglie, and Schrodinger ”Their approach stemmed from De Broglie’s matter wave concept known as “Wave Mechanics” or “Quantum Mechanics” ” Bohr’s model was inefficient for atoms other than hydrogen or poly-electronic atoms ” This new approach to a model of the atom focused on the concept of wave functions ” Since electrons are particles and therefore have wave properties ” Schrodinger viewed the electron as a standing ave ” Standing waves must have whole numbers of half wavelengths in any motion ” As an electron, this means that the hydrogen atoms could only have certain circular orbits with a circumference that whole number of wavelengths will fit. ” All other orbits would be destructive in nature and would not exist ” Schrodinger’s mathematical work is simplified to : HV = EV ” V is called the wave function with the coordinates of its 3d space position ” A wave function is called an orbital (this is not he Bohr orbit) ” The Hydrogen electron in a Is orbital is not moving around the nucleus in a circular orbit ” It is still unknown how electrons are moving 1.

Principle Quantum Number ” represented by the letter “n” ” it can only have positive integer values ” n determines the size of the orbital ” it is the energy level in the electron configuration 2. Angular Momentum Quantum Number ” represented by the letter “l” ” it has values from O to n-l ?” I is the sub-level and shape in the electron configuration 3. Magnetic Quantum Number ” represented by ml ” it has values between -l and I ” ml is the orbital ” it is the probability of where the electrons are; however, the electron is there only 90% of the time 4 Electron Spin Quantum Number ” represented by ms ” it has values of -1/2, 1/2 , and + or – 1/2 ” this is the direction in which an electron spin either “up” or “down”