1. What it Means: The periodic table was first arranged based on similarities in chemical and physical properties, and atomic mass. When atomic number was discovered by Mosley, and we found new elements, we found that they fit nicely into the original idea for the periodic table first proposed by Mendeleev.

7. What it means: Atoms are held together by the electrical attraction between protons and electrons, and molecules are held together by attraction between two atoms. Molecules are formed by the sharing of electrons; sharing completes the valence of each atom (usually!). Ions are formed when atoms gain or lose electrons; Ionic bonds form when oppositely charged ions attract each other. Metallic bonds share outer electrons among many metal atoms. “Nuclei awash in a sea of flowing electrons”

11. Solids: Particles sit there and vibrate Liquids: Particles in contact with each other and moving Gases: Particles flying around running into things

12. Simple Rule: Most elements form a full valence of eight electrons. Show these electrons by putting one on each side of the symbol, doubling up only when there is one electron on each side. Hydrogen and Helium have a full valence of two electrons (usually shown on the top of the element symbol.

13. In any chemical reaction, matter is neither created or destroyed. Stoichiometry is the quantitative study of the reactants and products in a reaction. The mass of products ALWAYS equals the mass of the reactants in a chemical reaction. Conservation of Mass/Energy applies to nuclear reactions, where mass/energy equivalence is given by Einstein’s famous equation: E = mc 2

15. This isn’t that interesting, but why does one mole of naturally occurring carbon have a mass of 12.011 grams? Remember, not all carbon is carbon 12, some is carbon 13 and 14.

16. You just need to know this. Kind of like one foot equals twelve inches. The more important piece is that you know that one mole of atoms has a mass equal to the atomic mass in grams

19. Atomic Motion: Solid atoms vibrate, liquid atoms move around each other but stay close, gas atoms bounce around their container. Gases Are: 1.) Compressible - Their pressure depends on volume 2.) In constant, rapid, random motion 3.) Not attracted to each other 4.) Very small with respect to the volume of the gas 5.) Undergoing many perfectly elastic collisions All atomic motion would stop at absolute zero, but we can’t get there...

20. Solids: Particles sit there and vibrate Liquids: Particles in contact with each other and moving Gases: Particles flying around running into things When gas particles collide with a surface, they create a force. Pressure is Force divided by Area (P=F/A)

26. A simple definition of an acid is a proton donor (H+) A base is a proton acceptor, the hydroxide ion (OH-) is a very good proton acceptor. Salts form + and - ions when dissolved in water.

31. So now you know! Buffers are very important in biological systems. Your blood has buffers in it, because changes in blood pH are bad, bad, bad...

32. Solutions can be solid, liquid or gas. Many solutions are liquids with solids or gases dissolved in them. Concentrations of solutions can be measured in a variety of ways.

33. Solute: Is dissolved in the solvent (often a gas or solid) Solvent: Does the dissolving (often a liquid) If solute and solvent are in the same phase, the solute is the one there is less of, and the solvent is the one there is more of...

35. Increase Temperature to Increase solubility of a solid in a liquid Decrease solubility of a gas in a liquid Increase pressure to increase solubility of a gas Smaller Particles dissolve faster than larger ones

37. Reactions that release energy = EXOTHERMIC Reactions that absorb energy = ENDOTHERMIC All chemical reactions involve energy. Energy changes are also involved in heating, cooling, and phase change.

40. This is why we put ice in coolers, and it takes a long time to evaporate away a pot of boiling water. This is also why we sweat on a hot day.

42. Want to speed up a chemical reaction? 1.) Heat it! 2.) Stir it! 3.) Increase the concentration of reactants! 4.) Make the particles smaller! 5.) Add a Catalyst! 6.) If a gas is involved, increase the pressure!

44. To increase the rate of a reaction: Increase the concentration of reactants Increase the temperature Increase the pressure Anything to make effective collisions more likely!

56. Radioactive isotopes are unstable, and will suddenly decay into other isotopes, and sometimes new elements.

58. Alpha: Large and Slow, like being hit with a bowling ball Can block with a sheet of paper Beta: Like being shot, faster, more dangerous Can block with your Chemistry book Gamma: Pure energy, very damaging Can block with ten feet of reinforced concrete