1. Attractive Forces part 1

2. Matter We have talked about the different states of matter and the differences in the behavior of particles in each state. What is it that determines the state of matter at room temperature? How does the nature of attractive forces in a material affect its properties?

3. Forces of Attraction Particles can be held together by various forces. These forces fall into different categories depending upon the nature of the attraction. There are forces that occur within the particles of a substance (within molecules or ionic compounds); these forces are between atoms or ions and tend to be stronger forces.

4. Forces of Attraction Other forces are attractions between particles of a substance (between separate molecules or between the atoms of atomic substances such as helium or xenon). These forces between particles tend to be weaker forces than those within the particles of a sample, with the notable exception of the attractions that exist between ions.

5. Strong Forces of Attraction Strong forces exist continuously in a substance due to sharing or transfer of electrons in a unit of a substance (molecules and ionic compounds). They vary in strength, depending upon the composition of the substance. The strength of the bond is indicated by how much energy is required to break the bond.

6. Strong Forces of Attraction

7. It can take from 400-4000 kJ/mol to break the strongest bonds, which result from the transfer of electrons between atoms to form ions. The nature of the ionic bond:

8. Strong Forces of Attraction It can take from 150-1100 kJ/mol to break covalent bonds, which indicates they are still very strong. Covalent bonds arise from sharing electrons:

9. Strong Forces of Attraction The previous slide indicated equal sharing, but it is also possible to have unequal sharing of electrons in a covalent bond (creating a polar bond).

10. Strong Forces of Attraction A comparison of substances exhibiting these strong forces of attraction shows the general progression from equal sharing of electrons to complete transfer. ionic and covalent bonding.flv polarity_of_molecules.flv

11. Strong Forces of Attraction Metallic bonding is a little different, and requires between 75-1000 kJ/mol to break.

12. References: http://www.chem.purdue.edu/gchelp/liquids/character.html http://www.chem.wisc.edu/~newtrad/CurrRef/BDGTopic/lab/Crystlab2.GIF http://lgfl.skoool.co.uk/uploadedImages/coord11.2_covalentbonding2_v2.gif http://www.dur.ac.uk/p.m.johnson/electric_circuits/images/dia_atom_cores.gif http://www.chemistry.wustl.edu/~courses/genchem/Tutorials/Water/images/nacl.jpg http://web.arc.losrios.edu/~borougt/DiamondStructure.jpg http://www.oocities.org/rjwarren_stm/PolarityOHbond.jpg http://www4.nau.edu/meteorite/Meteorite/Images/HydrogenBond.jpg http://cost.georgiasouthern.edu/chemistry/general/molecule/polar.htm http://virtual.yosemite.cc.ca.us/webbg/chem101/ch11lecture/intermolecforces.htm http://www.grandinetti.org/resources/Teaching/Chem121/Lectures/BondPolarity/ColvanttoIonic.gif http://www.drkstreet.com/resources/metallic-bonding-animation.swf http://www.chem.ufl.edu/~itl/2045/matter/FG11_002.GIF http://mysite.verizon.net/kdrews47/interactions/ldf.gif http://www.colorado.edu/physics/2000/applets/h2ob.html http://antoine.frostburg.edu/chem/senese/101/liquids/faq/h-bonding-vs-london-forces.shtml http://cost.georgiasouthern.edu/chemistry/general/molecule/forces.htm http://www.bbc.co.uk/scotland/learning/bitesize/higher/chemistry/images/bonding_fig11.gif http://www.northland.cc.mn.us/biology/Biology1111/animations/hydrogenbonds.html http://www.chem.purdue.edu/gchelp/liquids/ioninddp.gif http://chemwiki.ucdavis.edu/@api/deki/files/3831/=160inducedipole.gif

13. References - Videos: http://www.youtube.com/watch?v=QqjcCvzWwww http://www.youtube.com/watch?v=LKAjTE7B2x0&NR=1 http://www.youtube.com/watch?v=LGwyBeuVjhV http://www.youtube.com/watch?v=cThvGD-o_90