1. Basic Chemistry What you may or may Not have learned in 8 th grade science…

2. Atomic Structure Within the nucleus of the atom: Protons - +1 charge Neutron - 0 charge Outside the nucleus Electrons - -1charge

3. Where are these Atoms Periodic Table of Elements 96% of life’s elements are HONC – 99% = CHNOPS

4. Close look at elements Atomic Weight = The mass of the nucleus of the atom Atomic Number = The number of protons

5. How to Draw Out Electron Shells

6. More about elements  Isotopes  Have more neutrons HOWEVER behave the same as the original because the protons and neutrons still balance each other out  Ions  Have one extra or one less electron  Carbon 13 or Carbon 14 (which is radioactive and used in research)  Molecules vs. Compounds  2H + O H 2 O All are molecules 1 molecule of water or a compound Compound – two or more elements bonded together products reactants

7. Bonding COVALENT BONDS – sharing of electrons between atoms Non polar – electrons are equally shared Polar – electrons are not equally shared (electrons get pulled towards a higher electronegative molecule

8. Water is polar covalent bonding

9. More Bonds  Ionic Bonds – one atom pulls the electron away from the other atom  Opposite charges attract each other

10. Perhaps one of you gentlemen would mind telling me just what is outside the window that you find so attractive...?"

11. Bonds Between Compounds Dipole - Dipole – forms weak bonds to make a new compound (while keeping the original intact) involves attaching the positve end to the negative end) Hydrogen Bonds – hydrogen covalently bonded to one atom will also be attracted to one another - 20x weaker then covalent bonds

12. Water Chemistry We just saw that Hydrogen Bonding effects water… It is a polar molecule - a positive and negative end … Water is cohesive – H bonds holding it together – that’s how water gets up a plant Water is adhesive – water will cling to other substances as well (meniscus) Surface Tension – at the interface between water and air is a highly ordered arrangement of molecules