120 likes | 215 Views
Basic Chemistry. What you may or may Not have learned in 8 th grade science…. Atomic Structure. Within the nucleus of the atom: Protons - +1 charge Neutron - 0 charge Outside the nucleus Electrons - -1charge. Where are these Atoms. Periodic Table of Elements.
E N D
Basic Chemistry What you may or may Not have learned in 8th grade science…
Atomic Structure Within the nucleus of the atom: • Protons - +1 charge • Neutron - 0 charge Outside the nucleus • Electrons - -1charge
Where are these Atoms Periodic Table of Elements 96% of life’s elements are HONC – 99% = CHNOPS
Close look at elements Atomic Weight = The mass of the nucleus of the atom Atomic Number = The number of protons
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 H2O 1 molecule of water or a compound reactants Compound – two or more elements bonded together products All are molecules
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
More Bonds • Ionic Bonds – one atom pulls the electron away from the other atom • Opposite charges attract each other
Perhaps one of you gentlemen would mind telling me just what is outside the window that you find so attractive...?"
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
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