1. ELEMENTS – Greek theory of physical world. All earthly objects are a mixture of: 1.EARTH (bottom – center of universe) 2.WATER (water covers earth) 3.AIR (air over water) 4.FIRE (highest – at top) 5.Ether = QUINTESSENCE (Latin) – substance whose natural motion is that most symmetrical and eternal of all conceivable motion = endless circles

2. ATOMIMC STRUCTURE ATOMS – not ‘indivisible’ particles of Democritus and Dalton, but have electrons, protons, and neutrons. Solar system model – central core (nucleus) with orbiting models Scale Atomic (Proton) Number = to the number of protons in nucleus. This number determines chemical species. Ion – atom with net electrical charge due to loss/gain of one or more electrons Isotopes – same atomic number, but different number of neutrons

3. Alchemy – develop substance to restore youth; turn base metal into gold Origin of some chemical symbols (Latin) → ELEMENTSYMBOLORIGIN OF SYMBOL CopperCuCuprum (cyprus, source of copper) GoldAuAurum ('shining dawn" IronFeFerrum LeadPbPlumbum ("heavy") MercuryHgHydrargyrum ("liquid silver") SilverAgArgentum ELEMENTS & THE PERIODIC TABLE

4. ELEMENTS – 92 natural elements MOLECULES – collection of atoms held by chemical bond ex. H 2 0 – water – 3 atoms C 6 H 12 O 6 – glucose – 24 atoms C 2 H 5 OH – alcohol – 9 atoms Chemical Bonding – involves electrons A.Ionic – transfer of electrons ex. NaCl (salt) : Na (ignites in air) Cl (poison gas) extra Na electron fills in outer Cl shell B. Covalent – mutual sharing of electrons ex. H 2 0electrons most of the time of O leaving the two hydrogens positive.

5. States of Matter 1.Solid – definite shape, atoms locked into position, most have regular pattern. 2.Liquid – atoms packed tightly but not as tight as to prohibit movement; has surface. 3.Gas – large distances between atoms/molecules 4.Plasma – completely ionized gas ‘Atomic Theory’ – explains many things ex. Odors and evaporation

6. Aristotle (384-322 B.C.) Greek philosopher, educator, scientist Student of Plato

7. Antiparticles and Antimatter Electron - Positron Pair (1932) Proton - Antiproton (same mass, opposite charge) 2 8 Creation vs Annihilation E = mc (c = speed of light : 3 x 10 m/s)