# Wave-Particle Duality Louis De Broglie (1924) Louis De Broglie (1924) –Proposed that ALL matter has wave and particle properties, not just electrons. –E.

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• Wave-Particle DualityLouis De Broglie (1924)Proposed that ALL matter has wave and particle properties, not just electrons.E = E E = h or E = hc/ & E = mc2hc/ = mc2 hc = mc2 h = mc = h/mc OR = h/mvExample: of baseball (mass = .2 kg and v = 30 m/s) of an electron (mass = 9.11 x 10-31 kg and v = 3 x 108 m/s)

• Wave Mechanical ModelSchroedinger (1887-1961)Developed the wave mechanical model of the atom (also known as the quantum mechanical model)He used the following equation to produce scatterplots that are now called electron cloudsE = 22me2/h2n2These electron clouds are areas in which there is a great probability of finding an electron (90%).The cloud is more dense where the probability of finding an electron is high.The cloud is less dense where the probability of finding an electron is low.This is called an orbital a region in space in which there is a high probability of finding an electron.

• http://scienceworld.wolfram.com/physics/SchroedingerEquation.htmlhttp://www.uark.edu/misc/julio/orbitals/index.html

• Is That It? - UncertaintyHeisenberg (1927)Said that because of size and speed it is impossible to know both exact position and momentum of and electron at the same time.This is referred to as the Heisenberg Uncertainty PrincipleTo see an electron we strike it with something of similar size and observe its behavior.We cannot see an electron directly.We use photons of energy to do this.

• Quantum MechanicsThe work of de Broglie, Schroedinger, Born, and Heisenberg led to the study of quantum mechanics and the wave mechanical model1. classical physicsdescribes the motion of bodies much larger than the atoms of which they are composed.energy can be gained or lost in any amount2. quantum physicsdescribes the motion of atoms and subatomic particles as waves.particles gain or lose energy in packets called quanta

• Energy Components in ElectronsEach component is given a letter & a name we call them quantum values1. n = principaldistance from the nucleus2. l = azimuthalangular momentum3. m = magneticinteraction with electromagnetic fields4. s = spin axial rotationUsing these we can pinpoint the location of an e-.

• Locationn = principal energy level (shell)n + l = energy sublevel (subshell); defines the type of orbital that the electron is inn + l + m = specific orbital (axis orientation)n + l + m + s = spin (exact electron), identifies the exact electron and its locationANALOGY

• Orbital TypesS-orbital = spherical shape, only 1 of themP-orbital = gumdrop or dumbell shape, 3 of them one on each axis (x,y,z)D-orbital = donut shape, 5 of themF-orbital = cigar shape, 7 of themEach orbital contains a max of 2 electronsOrbit path of an electron (according to Bohr)Orbital region in space where there is a high probability of finding an electron

• Energy level = the number of orbital typesTotal number of orbitals in an energy level = n2Total number of electrons in any energy level = 2n2

ENERGY LEVELSORBITAL TYPES# OF ORBITALS# OF ELECTRONSn = 1s12n = 2s,p48n = 3s,p,d918n = 4s,p,d,f1632n = 5s,p,d,f,g2550