Semester 1 Review Questions for Exam Completion Complete each sentence or statement. 1. The part of an ecosystem where an organism lives and feeds is called the organism s 2. All the biotic and abiotic factors in an area together make up a(n) 3. Prairie dogs, snakes, and grass make up a level of ecological organization called a(n) 4. All the prairie dogs in one area are an example of a(n) 5. Water, sunlight, and soil are factors in an ecosystem. 6. Two abiotic factors that are needed for photosynthesis are sunlight and 7. Scientists who study how living things interact with the environment are called 8. The method of estimating involves multiplying the number of organisms in a small area to find the number in a larger area. 9. Observing animal tracks is an example of observation, which is used to estimate population size. 10. A group of zebras breaking off from a herd decreases the size of the herd population through 11. The major way that populations increase in size is through the of offspring. 12. If food is scarce, it becomes a factor that prevents population growth. 13. A lack of places to build nests is an example of as a limiting factor for a population of birds. 14. The thick fur of a polar bear is a(n) that allows the bear to live successfully in its environment. 15. Ticks feed on the blood of mice in a symbiotic relationship called 16. A close relationship between two species that benefits at least one of the species is known as 17. The struggle of two species to occupy a certain niche in an ecosystem is an example of 18. A hawk building a nest on the arm of a cactus without hurting the cactus is an example of the symbiotic relationship called 19. A flea is a parasite that lives on a(n) such as a dog. 20. The study of how living things interact with each other and with their environment is called 21. Bacteria and fungi are known as because they break down the remains of organisms. 22. The energy role of a grizzly bear is that of a(n) because it cannot make its own food.
23. A diagram called a(n) shows how much energy is available at each level of a food web. 24. The least amount of energy is available at the level of an energy pyramid. 25. The energy role of the first organism in a food chain is always a(n) 26. An organism that eats only plants is a consumer. 27. Water vapor turns into droplets of liquid water in the process of 28. Water from a lake changes to the gas state in the process of 29. Certain bacteria change nitrogen gas into a usable form in a process called 30. Producers use carbon from the gas to make sugars and starches. 31. The distribution of species has been affected by the slow movement of Earth s continents called 32. Small, light organisms such as baby spiders can be dispersed by 33. Mountains and deserts that are difficult for organisms to cross are barriers to dispersal. 34. Temperature and precipitation determine an area s, which can limit dispersal of organisms. 35. The biome receives less than 25 centimeters of rain a year and may have large temperature shifts every day. 36. The soil that is frozen all year in the tundra is called 37. The neritic zone over the continental shelf is part of the biome. 38. The part of the open ocean that receives enough light for floating algae to carry out photosynthesis is called the zone. 39. species such as lichens are the first to grow in an area with no soil. 40. The type of succession that occurs in an area where an ecosystem previously existed is called succession. 41. A(n) is a substance that cannot be broken down into any other substance by either chemical or physical means. 42. In a(n) change, elements and/or compounds rearrange to form different materials. 43. Atoms are held together by forces known as 44. A precipitate is a that forms from solution during a chemical reaction. 45. A subscript shows the number of of an element in a molecule. 46. The principle of states that during a chemical reaction, matter is not created or destroyed. 47. A reaction in which one element replaces another in a compound or in which two elements in different compounds trade places is called a reaction. 48. A chemical reaction that releases energy in the form of heat is a(n) reaction.
49. The is the amount of one material present in a given volume of another material. 50. A fuel is a material that will release when it burns. 51. When added to a fire, water and prevents the fuel from coming in contact with oxygen. 52. One of the most effective ways to fight a small fire is to use a 53. Two or more atoms may combine to form a 54. The process of dissolving sugar in water is a change. 55. The production of a gas when acid is added to a sample of chalk is an indication of a reaction. 56. The of a compound shows the ratio of elements present in the compound. 57. In a reaction, the products are simpler substances than the reactant. 58. The is the minimum amount of energy that must be added to start a chemical reaction. 59. A material used to decrease the rate of a reaction is called a(n) 60. A wet log will not burn easily because a large amount of must be added to the log to evaporate the water. 61. Neutrons are particles that have charge. 62. Chemical bonds form when valence electrons are between atoms. 63. In the periodic table, atoms are arranged from left to right and from top to bottom in order of increasing 64. Group 18 elements, also known as the noble gases, with other elements. 65. Nitrate (NO 3 ), ammonium (NH 4 + ), and carbonate (CO 3 2 ) are examples of ions. 66. When ions having a charge of 2+ form bonds with ions having a charge of 2, the charge on the resulting compound is 67. Ionic compounds that dissolve in water conduct electricity because they 68. Bonds that form between two nonmetal atoms usually are bonds. 69. Molecular compounds that dissolve in water do not conduct electricity because no are present. 70. Fluorine (F 2 ) is a molecule because the valence electrons are shared equally between the two fluorine atoms. 71. A naturally occurring solid that has a and a definite chemical composition is called a mineral. 72. are very energetic particles moving about in the space outside the nucleus. 73. A neutral atom never has more than valence electrons. 74. Elements in the same row of the periodic table are in the same
75. Elements in Group 17 (the halogens) are the reactive nonmetals. 76. Elements in Group 1 lose one electron to form ions with a charge. 77. When an ionic compound forms, the total number of positive charges and the total number of negative charges must be 78. In a double covalent bond, electrons are shared between two atoms. 79. Because the electrons in a molecule of hydrogen fluoride (HF) are more strongly pulled toward the fluorine atom, the molecule is 80. A is a mixture that appears uniform throughout and whose particles cannot easily be separated. 81. When a solution forms, particles of a solute and become surrounded by particles of the solvent. 82. If you can continue to add more solute to a solution, the solution is said to be 83. The presence of a solute makes it harder for solvent molecules to escape when heated, and so the boiling point of a solution is than that of the pure solvent. 84. A(n) is a compound that tastes sour and reacts with some metals. 85. A(n) is a compound that turns litmus blue and is often found in soaps and detergents. 86. Substances that form hydrogen ions when released in water are called 87. When the ph is high, the concentration of hydrogen ions is 88. In a reaction of an acid with a base, the ph changes to a value that is closer to 89. Because it will dissolve so many solutes, is sometimes called the universal solvent. 90. Ionic and polar compounds in water because water molecules are polar. 91. At the same concentrations, strong acids produce more than weak acids. 92. Foods such as oranges, tomatoes, and apples have a ph that is than 7. 93. A(n) is an ionic compound produced from the neutralization of an acid with a base. 94. Acids are, which means that they eat away at other materials. Short Answer
95. Describe two things the prairie dogs need to live that they obtain from their habitat. 96. What is the smallest unit of organization in an ecosystem? Give two examples from the diagram. 97. Describe one of the prairie dog s adaptations and how it helps the prairie dog to survive. 98. What level of ecological organization do all of the owls in a certain area represent? 99. Is the prairie soil a biotic factor or an abiotic factor? Explain your answer. 100. Describe three factors that could limit the growth of the prairie dog population.
101. How was the pheasant population changing at Point A? 102. Which letter marks the peak of the pheasant population? 103. What happened to the pheasant population between Point B and Point C? 104. What are some possible explanations for the change in pheasant population between Point B and Point C? 105. In 1990, a large resort hotel was built on the island where these pheasants live. Explain how this might have affected the pheasant population. 106. What was the density of pheasants in 1968, 1976, and 1990? 107. Which organisms shown are producers? 108. Which organisms shown are consumers? 109. What would happen to the other organisms if all the plants in this ecosystem died? 110. Use the organisms pictured in this ecosystem to construct a food chain. 111. Approximately what percentage of the energy in the plants is passed on to the animals that eat them? 112. Why are there relatively few third-level consumers like bears in an ecosystem? 113. Which number represents the organisms responsible for converting nitrogen gas into a usable form of nitrogen? 114. Which number represents the form of nitrogen that can be used by plants? 115. Describe three roles bacteria play in the nitrogen cycle. 116. Explain the role of an animal such as the horse in the nitrogen cycle. 117. Which number represents a group of organisms that break down the wastes and remains of other organisms? 118. On what part of a plant do the organisms represented by number 8 live?
119. Is the reaction that occurs in the diagram endothermic or exothermic? Explain. 120. When the candle was lit, a pool of liquid wax formed in the area around the wick, and then spilled over the side and resolidified. Does this observation refer to a physical change or a chemical change? Explain. 121. If the candle is covered by a large glass beaker, the flame will go out. How does the beaker affect the conditions described by the fire triangle? 122. If the products formed from the burning candle are mostly carbon (C), carbon dioxide (CO 2 ), and water (H 2 O), what elements were in the reactants? How do you know? 123. The flame from the candle gives off black smoke. Does this statement describe evidence for a physical change or a chemical change? Explain. 124. Candles often are made of several different kinds of waxes, and sometimes colorful dyes and pleasing scents. Does this statement describe a compound or a mixture? Explain.
125. What type of chemical reaction is represented in the diagram? Explain. 126. How would the mass of water formed in the reaction compare to the mass of oxygen that reacts? 127. Identify the reactant(s) and product(s) of the reaction. 128. Where does the water come from in the reaction? 129. What is the purpose of the burning splint in the reaction? 130. Write a balanced equation for the reaction. 131. List three elements from the group containing the most reactive nonmetals. 132. In each period, how does the number of electrons in each kind of atom change from left to right between Groups 1 and 2? Explain how you know.
133. How many atoms of a Group 17 element would be needed to react with one atom of a Group 2 element? Explain. 134. In an electron dot diagram of aluminum (Al), how many dots should be drawn around the element s symbol? Why? 135. Which group of elements loses electrons most easily? 136. Which group contains elements with two valence electrons? 137. How do protons, neutrons, and electrons differ in charge? 138. Where and what is the electron cloud of an atom? 139. What happens to the solubility of potassium nitrate (KNO 3 ) as the temperature rises? 140. According to the graph, which of the compounds is most soluble at 0 C? Which is least soluble at 100 C? 141. Compare the solubility of sodium nitrate (NaNO 3 ) to that of ammonia (NH 3 ). 142. How many grams of potassium nitrate (KNO 3 ) will settle out when a saturated solution containing 100 grams of water is cooled from 70 C to 50 C? 143. At a high temperature, what other compounds besides ammonia (NH 3 ) have a lower solubility than that of potassium nitrate (KNO 3 )? 144. At 70 C, 60 grams of ammonium chloride (NH 4 Cl) are added to 100 grams of water. What will happen if 10 grams more of ammonium chloride are added to the solution? Explain.
145. Use the ph scale to predict how the taste of an apple and a lemon would compare. Which has the more sour taste? Explain. 146. In terms of ph, explain what would happen if you mixed vinegar with a solution of ammonia. What type of products would form? 147. What does the ph of drain cleaner tell you about the dangers of such a product? 148. What color would litmus paper turn in a solution of baking soda? Explain your answer in terms of ph. 149. Why does soap taste bitter? 150. What does the ph of water tell you about how the water differs from the other items shown in the diagram?