March 13, 2016March 13, 2016March 13, 2016 GSCI 163 Spring 2010 Surprising Experimental Results  Atomic spectra Atoms are found to give off unique colors of light rather than the rainbow type spectra of a normal light bulbAtoms are found to give off unique colors of light rather than the rainbow type spectra of a normal light bulb Experiment last class illustrated this.Experiment last class illustrated this. Do you understand this result?Do you understand this result?

March 13, 2016March 13, 2016March 13, 2016 GSCI 163 Spring 2010 Surprising Experimental Results  BB radiation  Photo-electric effect  … Knowing the problems is irrelevant for this class but recognizing that a new approach was introduced and the consequences of this approach for atoms is essential.

March 13, 2016March 13, 2016March 13, 2016 GSCI 163 Spring 2010 Add QM  Every atom has a set of energy levels 1,2,3,4...  The levels are made up of orbitals labeled by a convention that we need to learn. S,P,D,FS,P,D,F

March 13, 2016March 13, 2016March 13, 2016 GSCI 163 Spring 2010Orbitals 1S 2S 2P 4F

March 13, 2016March 13, 2016March 13, 2016 GSCI 163 Spring possible transitions each one a different but fixed amount of energy is released or absorbed in order to jump down or up. smallest largest

March 13, 2016March 13, 2016March 13, 2016 GSCI 163 Spring 2010 Behave like an atom  Throw a ball when you jump down.  Catch a ball to jump up  Ball must match the jump.

March 13, 2016March 13, 2016March 13, 2016 GSCI 163 Spring 2010 spin  Electrons have a new characteristic SPIN  Spin up  Spin down

March 13, 2016March 13, 2016March 13, 2016 GSCI 163 Spring 2010 Need to know  Light is quantized (orbital jumps) and a particle of light is called  photon  Orbital structure and names (previous diagram)  1s 2s 2p 3s 3p 3d 4s 4p 4d 4f  Electron has spin  Pauli exclusion: No two electrons can occupy the same state (orbital)  Spin and Pauli  2 electrons per orbital  Orbitals are grouped into shells  The orbital configuration remains roughly the same for each atom (subtle) so that the shell structure is a general characteristic of all atoms.  Electron configuration is represented as 1s 2 2s 2 2p 3 1s 2 2s 2 2p 3  The last or highest shell for an atom is the valence shell.  The valence shell determines the chemistry and properties. 2s 2 2p 3 2s 2 2p 3  This orbital structure has a repeating pattern 2s 2 2p 3 3s 2 3p 3 4s 2 4p 3 5s 2 5p 3 2s 2 2p 3 3s 2 3p 3 4s 2 4p 3 5s 2 5p 3 B Al Ga In B Al Ga In BUILD PERIODIC TABLE

March 13, 2016March 13, 2016March 13, 2016 GSCI 163 Spring 2010

March 13, 2016March 13, 2016March 13, 2016 GSCI 163 Spring 2010  Metals  Non-metals  Noble gases  Groups  Periods  Others  lanthanoids …

March 13, 2016March 13, 2016March 13, 2016 GSCI 163 Spring 2010  Noble gases don’t interact  Metals conduct  Nuclear charge (number of protons)  Mass of atoms

March 13, 2016March 13, 2016March 13, 2016 GSCI 163 Spring 2010 PT atom size

March 13, 2016March 13, 2016March 13, 2016 GSCI 163 Spring 2010 First Ionization  energy required to remove first electron

March 13, 2016March 13, 2016March 13, 2016 GSCI 163 Spring 2010 Electronegativity & Electron affinity  Ability to add an electron Noble gasses do not accept electrons Electronegativity  TREND Electron Affinity  Measure energy released when electron added released when electron added

March 13, 2016March 13, 2016March 13, 2016 GSCI 163 Spring 2010 Periodic Table  What does it tell us about chemistry? Properties of atoms in the tableProperties of atoms in the table  From where does this structure come? Orbital structure and fillingOrbital structure and filling