Ch. 4 - Atomic Structure

Ch. 4 - Atomic Structure

Electron Cloud Model •

Niels Bohr, Louie De Broglie, Erwin Schrödinger, Werner Heisenberg

•

Energy Levels, sublevels, orbitals

•

Valence electrons

•

Lewis dot structures

Neils Bohr’s Model 

  

Quantum Mechanical Model  Louis De Broglie, 1923: electrons behave like waves and

like particles “wave-particle duality”  Erwin SchrÖdinger, 1926: the electrons are found in a cloud and orbitals surrounding the nucleus…….where the cloud is most dense, that’s probably where the electrons are.  Werner Heisenberg- 1928: Is NOT possible to know the EXACT location and VELOCITY of an electron

Today’s electron cloud  There are 7 energy levels in the

electron cloud… these correspond with the 7 rows on the Periodic Table of elements  Within the energy levels there are

four sublevels: s,p,d, & f  Within the sublevels, there are

orbitals– Regions in the electron cloud where there is a 90% probability of finding an electron.

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Sublevels and Orbitals

http://www.youtube.com/watch?v=yKgSSPkgldk

http://www.youtube.com/watch?v=K-jNgq16jEY

https://www.youtube.com/watch?v=Ewf7RlVNBSA https://www.youtube.com/watch?v=sMt5Dcex0kg

Electrons  Valence electrons – electrons in the last

energy level….. These are the electrons that are involved with bonding  Lewis dot diagrams-

• Elemental symbol • Dots represent valence e’