1. Ch 2 The Chemical Basis of Life Element- substance that cant be brokendown into simpler substances. # of protons makes each unique

2. Atom smallest unit of matter Composed of: 1. Protons, +, in nucleus 2. Neutrons, o, innucleus 3. Electrons, -, orbitnucleus in shells orlevelshttp://www.youtube.com/watch?v=sWVX_rGzzQU&feature=relatedAtom animation 3. GoldMercury 4. Define & distinguish among atomicnumber, mass number, atomic weight, andvalence Valence is the number of electrons needed to fill theoutermost shell of an atom. 5. Interactions between atoms: Atoms strive to fill their outer shell w/ e-. Todo this theyll share e- or steal e- 1st level max of 2 2nd level 8 6. Is this sodium atom satisfied? What couldit do? 7. Compare these twoWhat do you notice is different? How doyou think that would affect its charge? + 8. Is Chlorine satisfied?What could it do? How do you think that would affect it? - 9. If I couldonly get rid Heyof this one Sodium,electron in my outer Ill takeshell Id be it! I satisfied!need one more to besatisfied!Hey, babyI +Hey, babysuddenly I feel the feel this same way.attraction Its like wehave thisto you. bond 10. Ionic bond attraction between opp.charged ions + charged ion ion with less electrons thanprotons - charged ion ion with more electrons thanprotons 11. Covalent bond - atoms share electrons to bond http://www.wellesley.edu/Biology/Concepts/Html/c ovalentbonding.html 12. Polar Covalent bond - atoms shareelectrons unequally to bond 13. Molecule- 2 or more atoms that share e- Represented by formulas Ex: H2 14. Water is SUPER! 15. Unique properties of H2O Bonds b/t the O and Hatoms in H2O - polarcovalent bond. Polar covalent bond unequal sharing ofelectrons. Occurs b/c O hogsthe electrons 16. Water is polarPolar one side is +and other side is Due to O hoggingelectrons. 17. 1. Orgs depend on the cohesion of water molecules. Cohesion when H bonds hold a substance together. Contributes to transport of water against gravity in plants.Adhesion the clinging of one substance to anotherEx: MiniscusSurface tension a measure of how difficult it is to stretch orbreak surface of a liquid. Due to H bonds Skin 18. H bonds make water molecules stick to each other Weak bonds between water molecules dueto its polarity. 19. Jesus Lizzard http://www.visionlearning.com/library/module_viewer.php?mid=57&l=&c3= Link above! 20. 2. Water contributes to Earths habitabilityby moderating temperatures.It absorbs heat from warmer air & releases heat into cooler air.Ice cools drinks by absorbing heatHeat measure of the total quantity of kinetic E.Temperature measure of the intensity of heat due to the average kinetic E of the molecules.Swimmer in ocean has a higher temp than water but the ocean contain far more heat due to its volume. 21. Specific heat amt of heat that must be absorbedor lost for 1 g of that substance to change itstemp by 1 C. measure of how well a substance resists changingits temp. Water - high specific heat. 1cal/g/C To increase temp of H2O heat must be absorbedto break H bonds. To decrease temp of H2O heat must be releasedto form H bonds. When enough H bonds areformed, its solid ice. This is why it actually gets a little warmer whenthe rain turns to snow heat is released when theH bonds form. 22. Why is water important to life?3. Cools orgs when they sweat, pant, or roll in mud b/c the hottest molecules are leaving the surface - evaporative cooling. 23. Why is water important to life?4. Oceans and lakes dont freeze solid b/c ice is less dense than water so it floats. Less dense b/c when H-bonds form, water molecules are farther apart. 24. Diffusion Diffusion = random movement ofmolecules high concentration to less Ex: smell of popcorn spreads The Diffusion Applet 25. Diffusion Continues until all molecules areevenly spread out. Dynamic equilibrium = concentrationof molecules are even but moleculesare still moving. Its how molecules get into & out ofour cells 26. Diffusion The faster the molecules aremoving, the faster diffusion willoccur. 27. Why is water important to life?5. Many substances dissolve in it because it ispolar. 28. Terms to knowSoluteSolventHydrophilicHydrophobic 29. Solute concentration in aqueoussolutionsMole equal in # to the molecular wt. butupscaled to gramsMolecular wt sum of wts of all atoms in amoleculeSo to obtain 1 mol of sucrose (C12H22O11):C = 12 (daltons) x 12 (atoms present) = 144H = 1 x 22 = 22O = 16 x 11 = 176Molecular wt = 342 g 30. molarity # of moles of solute per liter ofsolutionSo to make a 1 molar solution ofsucrose you would add 1 liter of waterto 342g of sucroseA 0.2 molar solution of sucrose?Add 1 liter of water to 68.4g ofsucrose (342 x 0.2) 31. Orgs are sensitive to changesin pHAcid substance that increases the H+ of a solutionBase substance that reduces the H+ of a solution & has more OH- ions. 32. pH scale In any solution the product of the H+and OH- is 10-14 from 0-14 used to show H+concentrations Each pH unit represents a tenfolddiff in the concentration of H+ pH declines as H+ increases