Modern Model of the Atom
- 1. Modern Model of The Atom • Rutherford’s Model: Pro’s and Con’s • Improved on (Thomson’s) Plum Pudding Model • Protons inside, Electrons outside • Couldn’t explain how electrons stayed outside
- 2. Niels Bohr and The Planetary Model of The Atom • Inspired by Niels Bohr the work of Bunsen and Kirchoff • Emission spectra of Spectrometer elements Bunsen and Kirchoff
- 3. Bohr: Electrons are ‘quantized’ • Emission spectra Emission Spectra • Electrons in of a Few Elements Energy Levels • Electrons • Ground State Ground State vs. Excited and Excited State State
- 4. Bohr Model=Planetary Model • Bohr’s Model Pro’s and Con’s • Explained small atoms well • Failed to explain where electrons were in larger atoms Nitrogen Atom
- 5. Quantum Mechanic Model of The Atom • Erwin Schrodinger and Werner Heisenberg Schrodinger • 1925-30 • Refined Bohr’s Model • Wave or Cloud Model of Electrons • Electrons in orbitals of Heisenberg differing energy
- 6. Quantum Mechanic Rules • Energy level (n=energy level) • Type of orbital (s,p,d,f) s-orbital • Shape of orbital p-orbital • sphere, dumbbell, rosette, d-orbital complex f-orbital • Number of Electrons in orbital Shapes • s=2; p=6; d=10; f=14 of Orbitals
- 7. Quantum Mechanic Rules Continued... • Aufbau Principle • electrons occupy orbitals of lower energy first • (s<p<d<f) • Hund’s Rule • electrons occupy adjacent orbitals before pairing • Pauli Exclusion Principle • electrons occupying the same orbital must have opposite spin
- 8. The Periodic Table: Where Are The S, P, D, and F Orbitals? s-orbitals d-orbitals p-orbitals f-orbitals
- 9. Orbital Diagrams and Electron Configurations • orbital diagrams show us where bonding occurs • We’ll do elements 1-10 • You will do elements 11-18, tonight Aufbau Diagram