#: ___ Scientist’s Name: _____________________ 2. Describe the biochemical basis of life and explain how energy flows within and between the living systems. a. Explain and compare with the use of examples the types of bond formation (e.g., covalent, ionic, hydrogen, etc.) between or among atoms. (DOK 2) Subatomic particles and arrangement in atoms Importance of ions in biological processes b. Develop a logical argument defending water as an essential component of living systems (e.g., unique bonding and properties including polarity, high specific heat, surface tension, hydrogen bonding, adhesion, cohesion, and expansion upon freezing). (DOK 2) c. Classify solutions as acidic, basic, or neutral and relate the significance of the pH scale to an organism’s survival, (consequences of having different concentrations of hydrogen and hydroxide ions). (DOK 2) Textbook ~ Chapter 6 DaBook ~ Sections 4.2 ~ 4.7 Chemistry of Life ppt Questions 1. ___ is the study of matter. 2. The building blocks of all matter are ___. 3. All atoms have the same general arrangement. The dense, positive center is called the ___. It contains positively charged particles called ___ & particles that have no charge called ___. Forming a cloud around the nucleus are even smaller, negatively charged particles called ___. These particles travel around the nucleus in certain regions know as ___. Because the first is the smallest, it can only hold ___ electrons. The second level is larger & can hold a maximum of ___ electrons. The third level is larger yet & can hold ___ electrons. 4. Label the parts of an atom. 5. Complete the following table. Subatomic Particle ii. iv. v. vii. viii. Location i. Charge iii. vi. ix. 6. Define elements. 7. There are over ___ known elements, ___ of which occur naturally. 8. Each element has a unique name and _______. 9. What are the rules for writing chemical symbols? 10. The _______ ________ of ________ is the organized illustration of all of the known elements. 11. Vertical elements are called ______ or ________. 1 12. Horizontal elements are called _______ or ______. 13. Label the box from the periodic table & explain each component. H 14. ___ on the periodic table tells the number of protons & electrons. 15. How are the numbers of neutrons determined? 1.0079 16. Define isotopes & explain how they are useful to scientists. 17. (True or False) Water is an element. 18. Define compound. 19. Atoms combine to become ___. For most elements, an atom becomes ___ when… 20. State, explain, and give examples of the octet rule. 21. Complete the following table. Types of Bond x. xiv. Interaction of Electrons xi. xv. xii. xvi. Result Example xiii. xvii. 22. Some atoms tend to _____ (lose) or ______ (gain) electrons more easily than other atoms. 23. Elements known as ______ always donate & _______ always accept electrons. 24. An atom that has lost or gained electrons is called an ______. 25. Metals become _______ when they lose electrons. 26. Nonmetals become _______ when they gain electrons. 27. List two characteristics of ionic compounds. 28. A calcium atom contains twelve protons, twelve neutrons, & twelve electrons. Describe the structure of a calcium atom. Use a labeled drawing to help you explain this structure. 29. Draw Bohr’s model for an oxygen atom. 1 30. Define van der Waals Forces. 31. Identify the bonds to the right as ionic or covalent. 32. Which type of bond is the most abundant in living things? 33. A chemical reactions is… 2 34. Clues of a chemical reaction include… 2 35. _______ describe the substances joined by bonds. 36. Scientists represent chemical reactions by writing ___which use symbols & formulas to represent each element or substance & an arrow indicates the process of change. 37. ________ are the starting substances on the left side of the arrow. 38. _______ are the substances formed during the reaction, on the right side of the arrow. 39. ________ _________ 40. Write a chemical equation for the reaction of glucose & oxygen. 41. The _____ states matter cannot be created or destroyed. 42. How is a chemical equation balanced? 43. Define activation energy. 44. Explain exothermic & endothermic reactions. 45. Define metabolism. Give an example. Extraordinary Properties of Water ppt Questions 46. 47. 48. 49. 50. What is the formula for a molecule of water? Which atom in water attracts more negative electrons? Water is a _______ molecule because it has an equal number of _______ and _______. What is water’s net charge? Water is called a _______ molecule because the oxygen end “acts” _______ charged and the hydrogen end “acts” _______ charged. 51. One hydrogen bond is _______, but many hydrogen bonds are ________. 52. How do hydrogen bonds form? PROPERTIES OF WATER 53. At sea level, water boils at _______________ and freezes at ____________. 54. What happens to the boiling point of water at higher elevations where the atmospheric pressure is less? 55. Where will it take longer for an egg to boil ---- in Death Valley or Mt. Everest? 56. Name 5 more properties of water that are important to life. 57. What is cohesion? 58. Cohesion produces ______ ______ when one water molecule attracts other _____ molecules. 59. What is surface tension a measure of? 60. How does the film produced by surface tension help organisms? 61. What is adhesion? 62. How does adhesion DIFFER from cohesion? 63. Adhesion produces ___________ ________ as water is attracted to and pulled into a tube. 64. What process in plants is due to capillary action (one word)? 65. Plants absorb water through their ________ and use ________ action or ________ to move water upward against gravity to the leaves. 66. Name 2 other things observed in nature that are the result of adhesion. 67. Define specific heat. 68. Water ______ a change in temperature and can absorb or release _________ amounts of energy with very little temperature change. 69. What is heat of vaporization? 70. In order to evaporate, water must break its _______ bonds. 71. When water evaporates from a surface, it removes a lot of ________. 72. What is water’s heat of vaporization? 3 73. In order for a gram of water at 100oC to change into steam at that same temperature, it must ____ ____ calories of energy. Therefore, which would contain more energy at 100 oC, steam or boiling water? 74. How does water warm the Earth? 75. Why does ice float in water? 76. Frozen water forms _______________ holding the molecules at fixed distances from each other. 77. Which is denser ---- ice or water? 78. Define homeostasis. 79. List 5 ways that water helps maintain homeostasis. SOLUTIONS & SUSPENSIONS 80. Solutions and suspensions are two types of ______ that both contain _______. 81. The _______ is the substance being dissolved and the ______ is what the substance is dissolved in. 82. What acts as a “universal solvent” because it dissolves so many substances? 83. How does a suspension form? 84. What keeps particles suspended? ACIDS, BASES, & pH 85. Write the equation for the dissociation (separation) of water and label the hydrogen & hydroxide ions? 86. What does the pH scale actually measure? 87. The pH scale ranges from ____ with a pH of ____ being neutral. 88. Where are acids found on the pH scale? 89. Where are the bases found on the pH scale? 90. Each pH unit represents a factor of _____ change in concentration. 91. How much stronger is a substance with a pH of 3 than a pH of 6. Show how you got your answer. 92. Acids produce a lot of ____ ions, while bases contain lots of ____ ions. 93. What is a buffer? 94. Buffers are produced by the body to ____ acids and bases to maintain homeostasis. 95. What pH do you think is best for most parts of the body --- cells, blood, etc? 96. In what pH range would you expect food/drink products to be? 97. In what pH range would you expect cleaning products to be? Look at the chart below and answer the following questions. 98. How much more acidic is an acid with a pH of 6 than water with a pH of 7? 99. How much more basic is a base with a pH of 9 than water with a pH of 7? 100. The line on the right hand side of the graph is not complete. Using your pencil or pen, draw in a line that completes the graph. 101. Looking at the graph, what shape indicates the neutral section for pH? 4 102. What is an example of a neutral substance? 103. What is an example of a basic substance? 104. How could you use this chart to help determine the strength of an acid or a base? 105. Why is pH important? PROPERTIES OF WATER BOOK INSTRUCTIONS FOR MAKING A BOOK: WHAT TO PUT ON EACH PAGE OF YOUR BOOK: NOTE LOWER RIGHT CORNER STARTING WITH PAGE 2 - NUMBER EACH PAGE IN THE FRONT COVER Write the book title - PROPERTIES OF WATER Sketch and color a water molecule In the upper left corner, write your name and number PAGE 1 (Frontside) Do not write on the back of the front cover. 5 Write the page title, UNIVERSAL SOLVENT, centered at the top of the page. Draw and color (Oxygen-RED and HydrogenBLUE) water molecules held together by hydrogen bonds Write, bullet, and answer these questions: o What is a solvent? o Why is water called a universal solvent? o What is a solute? o Which type of molecules, polar or nonpolar, dissolves in water? o Are materials that dissolve in water hydrophobic or hydrophilic? PAGE 1 (Backside) Write the Page title, POLARITY, centered at the top of the page. Draw and color (Oxygen-RED and Hydrogen- BLUE) water molecules held together by hydrogen bonds Write, bullet, and answer these questions: o What is meant by polarity? o Which end of the water molecule attracts most of the electrons and acts negative? o Which end acts positive? o How do water molecules act like “little magnets”? PAGE 2 (Frontside) Write the Page title, COHESION, centered at the top of the page. Sketch and color the water droplet Write, bullet, and answer these questions: o What is cohesion? o Cohesion produces _____ tension as the water molecules hold tightly together. o How do living things like insects use surface tension? PAGE 2 (Backside) Write the Page title, ADHESION, centered at the top of the page. Sketch and color the picture below. Adhesion pulls the liquid up the sides of the straw (capillarity). Write, bullet, and answer these questions: o Define adhesion. o Adhesion produces an effect called ___ action when you place a straw in a liquid. o Draw & explain a meniscus in relation to adhesion. o Explain how adhesion and cohesion help plants move materials. LAST PAGE (Inside of back cover) Write the Page title, INSULATION, centered at the top of the page. 6 Sketch and color the ice crystal. Write, bullet, and answer these questions: o When is water the densest? o Explain why ice floats? o How is a lake or river that freezes over helpful to the organisms in the water? Properties of Water Lab Part 1 - Drop Shape & Adhesion of Water Materials: wax paper dropper microscope slide water Procedure: 1. Predict what the shape of water will be on a piece of wax paper. 2. Predict what the shape of water will be on a clean microscope slide. 3. Using the dropper, place 2 or 3 drops of water on the wax paper & microscope slide. Draw the results below. 4. What shape were the drops of water on each surface? 5. Put another glass slide on top of the one with the water drops. Being very careful, try to pull the slides apart easily. What happened? 6. Which surface displayed the property of adhesion? 7. Define adhesion. Part 2 - Capillary Action of Water Materials: 100 mL graduated cylinder Vis-A-Vis marker stopwatch water chromatography paper strip (27 cm) Procedure: 1. Predict how fast you think that water will climb up a piece of absorbent paper 2 cm wide. I predict that water will travel up the strip __________/_________. (distance/time) 7 2. Using a 100 mL graduated cylinder, place 10 mL of water into the Time Distance cylinder. (cm) 3. Place a single drop of ink from the marker 4 cm from one end of the paper strip & let it dry. Write group members names on the opposite 5 end of the strip. 10 4. Lower the end of the strip with the mark into the graduated cylinder 15 until it reaches the bottom of the cylinder & fold the extra section of the strip over the top of the cylinder. 20 5. The ink mark should be a couple of cm above the water level. 25 6. Copy the data table on the right. Record the starting time. 7. Observe the distance that the water travels up the strip every five 30 minutes for 45 minutes. Record your observations on the table. 35 8. Hang the strip on the window blinds & let it dry. 40 9. Staple the dried paper strip onto your notebook page & label each color on the strip. 45 10. How did the ink change? 11. Explain the results including capillary action, polar molecules, & hydrogen bonding. 12. Your notebook paper should include: group members’ names & numbers, hypothesis, data table, answers to #11 & #12, & your labeled strip. Part 3 - Cohesion of Water Materials: 2 - 10 mL graduated cylinders glass stirring rod food coloring cooking oil water Procedure: 1. Put 8 mL of water into a 10 mL graduated cylinder. 2. Gently add 2 mL of cooking oil by tilting the cylinder of water slightly & letting the oil run slowly down the inside of the cylinder. 3. Explain what happened. 4. Set the mixture aside. 5. Get another clean 10 mL graduated cylinder & place 8 mL of cooking oil in it. Add 2 mL of water to the oil. 6. Explain what happened. 7. Which is less dense, oil or water? 8. This characteristic behavior of water & oil is of critical importance for living things & determines many properties of the cell. Use the illustration to the right to explain how. 9. What mechanism causes water molecules & oil molecules to separate from one another? Your explanation should include the following - polar/nonpolar molecules, hydrophobic, effects of polarity on molecular interactions, & H bonding. 10. Set the mixture aside. 11. Predict what will happen if you add a few drops of a water-soluble dye solution to each of the above graduated cylinders containing water & oil. 12. Add a few drops of dye to each cylinder. Use a glass stirring rod to penetrate the interface between each layer, giving the dye access to both water & oil. How does the dye behave in each cylinder? Does it diffuse into the oil? Into the water? 13. Stir the contents of each cylinder with a stirring rod & then let it sit. Will the contents remain mixed? Why? 14. Explain why this happens. Your explanation should include the following - polarity, hydrophobic, polar/nonpolar molecules, solution, & H bonding. Part 4 - Disruption of Cohesion of Water Materials: 8 100 mL Beaker water dish detergent dropper cooking oil Procedure: 1. Put 80 mL of water in a clean 100 mL beaker. Predict what will happen if you add one small drop of oil to the water using a medicine dropper. 2. Add the drops of oil to the water. Was your prediction correct? Add more drops of oil if necessary to see it clearly. Describe your observations including polar & nonpolar layers & why it occurs. 3. Predict what will happen if you add a drop of detergent to the beaker. 4. Add one drop of detergent to the beaker of water. Was your prediction correct? Explain your observations including how the detergent works in molecular terms & the disruption of cohesion. 5. Explain why enormous oil spills in the ocean are difficult to clean up. Questions: 1. How does water rise from the roots of a tree to the very top? 2. How do insects walk on the water? 3. Why does ice float rather than sink? 4. Why do people become seriously ill, or die, if they go without liquid for a week or so? 5. How would life in a lake be affected if ice sank & lakes froze from the bottom up? #: _____ Name _____________ Water Lab Part 1 – Drop Shape & Adhesion of Water: 1. Predict what the shape of water will be on a piece of wax paper. 2. Predict what the shape of water will be on a clean microscope slide. 3. Results: 4. What shape were the drops of water on each surface? 5. What happened? 6. Which surface displayed the property of adhesion? 7. Define adhesion. Part 2 - Capillary Action of Water: 1. I predict that water will travel up the strip ________/_________. (distance/time) Data: 9 Time 5 10 15 20 25 30 35 Distance 8. How did the ink change? Staple the paper strip onto your answer page & label each color on the strip. 9. Explain the results including capillary action, polar molecules, & hydrogen bonding. Part 3 - Cohesion of Water: 3. Explain what happened. 6. Explain what happened. 7. Which is less dense, oil or water? 8. Explain using the illustration. 9. What mechanism causes water molecules & oil molecules to separate from one another? 11. Predict. 12. How does the dye behave in each cylinder? Does it diffuse into the oil? Into the water? 13. Will the contents remain mixed? Why? 14. Explain. Part 4 – Disruption of Cohesion of Water: 1. Predict what will happen if you add one small drop of oil to the water using a medicine dropper. 2. Was your prediction correct? Describe your observations including polar & nonpolar layers & why it occurs. 10 3. Predict what will happen if you add a drop of detergent to the beaker. 4. Was your prediction correct? Explain your observations including how the detergent works in molecular terms & the disruption of cohesion. 5. Explain why enormous oil spills in the ocean are difficult to clean up. Part 5 – Surface Tension Penny Lab: 1. # drops of water you think will fit on a penny ____ (Hypothesis) 2. Test 1 Test 2 Test 3 Test 4 Test 5 AVERAGE 3. How does soap affect the water’s surface tension? 4. Test 1 Test 2 Test 3 Test 4 Test 5 Average Soapy Water 5. Was your hypothesis correct? ______________ 6. Write the correct statement. 7. Did they get the same results? __________ 8. Which set of trials represented your control: tap water or soapy water? Questions: 1. How does water rise from the roots of a tree to the very top? 2. How do insects walk on the water? 3. Why does ice float rather than sink? 11 4. Why do people become seriously ill, or die, if they go without liquid for a week or so? 5. How would life in a lake be affected if ice sank & lakes froze from the bottom up? 12