Solution Manual for Biology Life on Earth, 11th Edition

Biology: Life on Earth w/ Physiology, 11e (Audesirk/Audesirk/Byers) Chapter 2 Atoms, Molecules, and Life 2.1 Multiple-Choice Questions 1) A substance with specific properties that cannot be broken down or converted into another substance is called a(n) A) element. B) molecule. C) ion. D) compound. E) mixture. Answer: A Diff: 1 Chapter Section: 2.1 Skill: Knowledge/Comprehension Learning Outcome: 2.1 Global L.O.: G1 2) If you examined the human body on a chemical composition basis, which of the following combinations of elements would be most common? A) O, C, P, S B) O, C, N, Na C) C, H, Ca, Cl D) C, N, Ca, S E) O, C, H, N Answer: E Diff: 2 Chapter Section: 2.1 Skill: Knowledge/Comprehension Learning Outcome: 2.1 Global L.O.: G1 3) The atomic number of an atom is defined as the A) number of electrons in the outermost energy level. B) total number of energy shells. C) number of neutrons in the atomic nucleus. D) number of protons in the atomic nucleus. E) total number of electrons and neutrons. Answer: D Diff: 2 Chapter Section: 2.1 Skill: Knowledge/Comprehension Learning Outcome: 2.2 Global L.O.: G1 1 Copyright © 2017 Pearson Education, Inc. 4) Phosphorus has an atomic number of 15, so what is the distribution of its electrons? A) The first energy level has 8 and the second has 7. B) The first energy level has 2, the second has 8, and the third has 5. C) The first energy level has 2 and the second has 13. D) The first, second, and third energy levels have 5 electrons each. E) The electron arrangement cannot be determined from the atomic number alone. Answer: B Diff: 2 Chapter Section: 2.1 Skill: Application/Analysis Learning Outcome: 2.2 Global L.O.: G1 5) Which four elements make up approximately 96% of living matter? A) Carbon, hydrogen, nitrogen, oxygen B) Carbon, phosphorus, hydrogen, sulfur C) Carbon, sodium, chlorine, magnesium D) Carbon, oxygen, calcium, sulfur E) Oxygen, hydrogen, calcium, sodium Answer: A Diff: 2 Chapter Section: 2.1 Skill: Knowledge/Comprehension Learning Outcome: 2.2 Global L.O.: G1 6) Imagine that you have been hired as a chemist and your first task is to examine a newly discovered atom. The paperwork you are given states that its atomic number is 110. What does this mean? A) The atom contains 110 protons. B) The atom contains 55 electrons. C) The atom contains 55 protons and 55 neutrons. D) The atom is an isotope. Answer: A Diff: 1 Chapter Section: 2.1 Skill: Application/Analysis Learning Outcome: 2.2 Global L.O.: G1 2 Copyright © 2017 Pearson Education, Inc. 7) Iron is an important element in human body cells. If iron has an atomic number of 26, what does this tell you about this element? A) An iron atom has 13 electrons and 13 protons. B) An iron atom has 13 protons and 13 neutrons. C) An iron atom has 26 protons. D) An iron atom is unable to become an isotope. Answer: C Diff: 2 Chapter Section: 2.1 Skill: Application/Analysis Learning Outcome: 2.2 Global L.O.: G1 8) Carbon-14 is often used for carbon dating, where scientists measure the rate of carbon-14 decay to determine the age of items. Carbon-14 contains six protons and eight neutrons. During the process of carbon-14 decay, one of its eight neutrons becomes a proton and an electron is emitted. Which of the following is the best explanation of what has occurred? A) The resulting atom has a more stable nucleus. B) The resulting atom is now a different element because the number of protons has changed. C) The resulting atom is still carbon-14. D) An ionic bond has formed. Answer: B Diff: 3 Chapter Section: 2.1 Skill: Knowledge/Comprehension Learning Outcome: 2.3 Global L.O.: G1 9) Radioactive isotopes are biological tools that are often used to A) measure the size of fossils. B) detect brain tumors and other important medical technologies. C) build up a store of calcium in a cell. D) increase the pH of blood. Answer: B Diff: 2 Chapter Section: 2.1 Skill: Knowledge/Comprehension Learning Outcome: 2.3 Global L.O.: G1 3 Copyright © 2017 Pearson Education, Inc. 10) For an atom to achieve maximum stability and become chemically inert, what must occur? A) Its outermost energy shell must be completely filled with electrons. B) The number of electrons must equal the number of protons. C) Electron pairs are shared. D) Ionization occurs. Answer: A Diff: 2 Chapter Section: 2.2 Skill: Application/Analysis Learning Outcome: 2.2 Global L.O.: G1 11) An atom’s nucleus is composed of A) protons only. B) neutrons only. C) protons and electrons. D) protons and neutrons. E) neutrons and electrons. Answer: D Diff: 1 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.2 Global L.O.: G1 12) The formation of ions involves the A) sharing of electrons. B) gain or loss of electrons. C) gain or loss of protons. D) sharing of protons. E) gain or loss of neutrons. Answer: B Diff: 2 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.2 Global L.O.: G1 4 Copyright © 2017 Pearson Education, Inc. 13) If a certain atom has a tendency to lose two electrons, that atom can then become a(n) A) polar molecule. B) ion. C) water molecule. D) isotope. Answer: B Diff: 2 Chapter Section: 2.2 Skill: Synthesis/Evaluation Learning Outcome: 2.2 Global L.O.: G1 14) The formation of sodium chloride (NaCl) is the result of A) covalent bonding. B) chemical unreactivity. C) attraction between opposite charges. D) repelling between the same charges. Answer: C Diff: 2 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.4 Global L.O.: G1 15) Atoms or molecules that have gained or lost electrons are called A) acids. B) bases. C) covalent. D) ions. E) buffers. Answer: D Diff: 2 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.4 Global L.O.: G1 5 Copyright © 2017 Pearson Education, Inc. 16) Most biological molecules are joined by A) peptide bonds. B) ionic bonds. C) hydrogen bonds. D) disulfide bonds. E) covalent bonds. Answer: E Diff: 2 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.4 Global L.O.: G1 17) Sulfur is an essential element in the human body, and studying its characteristics is important in understanding human physiology. Sulfur atoms have six electrons in their outer shell. Based on this information, which of the following is TRUE? A) Sulfur can form important molecules using covalent bonds. B) Sulfur is inert. C) Sulfur is an important isotope of hydrogen. D) Sulfur has eight electrons in its outer shell. Answer: A Diff: 2 Chapter Section: 2.2 Skill: Synthesis/Evaluation Learning Outcome: 2.2 Global L.O.: G1 18) Free radicals contain unpaired electrons in their outermost energy shell, so they react readily with other atoms or molecules to reach a more stable state. Which of the following could potentially be a free radical? A) Fluorine (atomic number 9) B) Helium (atomic number 2) C) Neon (atomic number 10) D) Magnesium (atomic number 12) Answer: A Diff: 2 Chapter Section: 2.2 Skill: Application/Analysis Learning Outcome: 2.4 Global L.O.: G1; G2; G4 6 Copyright © 2017 Pearson Education, Inc. 19) Free radicals are considered dangerous because they A) attack the atomic nucleus. B) emit dangerous radiation. C) steal electrons from other atoms, causing those atoms to become unstable. D) damage oxygen and cause it to become an antioxidant. Answer: C Diff: 2 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.4 Global L.O.: G1 20) Scientists recommend a diet rich in antioxidants to stay healthy. What occurs at the atomic level to explain this recommendation? A) Antioxidants prevent free radicals from attacking other atoms or molecules. B) Antioxidants cause an increase in pH, which is necessary for neutrality in cells. C) Antioxidants steal electrons, which gives cells extra energy. D) Antioxidants are inert and do not interact with free radicals. Answer: A Diff: 2 Chapter Section: 2.2 Skill: Application/Analysis Learning Outcome: 2.4 Global L.O.: G1; G5 21) Which of the following best explains why a particular atom may not form compounds easily? A) The atom has no electrons. B) The atom has an uneven number of protons. C) The atom has seven electrons in its outer shell. D) The atom’s outer energy shells are completely full. Answer: D Diff: 2 Chapter Section: 2.2 Skill: Application/Analysis Learning Outcome: 2.2 Global L.O.: G1 7 Copyright © 2017 Pearson Education, Inc. 22) The element carbon has atomic number 6. Carbon most likely A) forms ionic bonds with other atoms. B) forms four covalent bonds. C) shares two electrons with another atom. D) donates two electrons to another atom. Answer: B Diff: 2 Chapter Section: 2.2 Skill: Application/Analysis Learning Outcome: 2.4 Global L.O.: G1 23) Sodium (Na), atomic number 11, has a tendency to lose an electron in the presence of chlorine. After losing the electron, Na has ________ protons in its nucleus. A) 10 B) 11 C) 12 D) 21 E) 22 Answer: B Diff: 3 Chapter Section: 2.2 Skill: Application/Analysis Learning Outcome: 2.6 Global L.O.: G1 24) Carbon has atomic number 6. Carbon most likely A) shares electrons. B) shares neutrons. C) loses electrons. D) shares protons. E) loses protons. Answer: A Diff: 1 Chapter Section: 2.2 Skill: Application/Analysis Learning Outcome: 2.5 Global L.O.: G1 8 Copyright © 2017 Pearson Education, Inc. 25) What does H-O-H represent? A) Atom of water B) Mixture including water C) Molecule of water D) Ionic bonding of water Answer: C Diff: 2 Chapter Section: 2.2 Skill: Application/Analysis Learning Outcome: 2.4 Global L.O.: G1 26) The atomic number of hydrogen is 1. Based on this fact, all of the following must be true of hydrogen gas (H2) EXCEPT that it A) is a stable molecule. B) uses covalent bonds to form the molecule. C) shares one pair of electrons between the two hydrogen atoms. D) is a polar molecule. Answer: D Diff: 2 Chapter Section: 2.2 Skill: Application/Analysis Learning Outcome: 2.5 Global L.O.: G1 27) Polar covalent bonds form when A) electrons are shared unequally between atoms. B) more than one pair of electrons is shared. C) ions are formed. D) an acid and a base are combined. E) atoms from two molecules are repelling each other. Answer: A Diff: 1 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.4 Global L.O.: G1 9 Copyright © 2017 Pearson Education, Inc. 28) Which of the following represents a molecule characterized by polar covalent bonding? A) NaCl B) H2 C) H2O D) O2 E) CH4 Answer: C Diff: 3 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.5 Global L.O.: G1 29) What type of bond is easily disrupted in aqueous solutions (one in which the solvent is water)? A) Covalent B) Polar covalent C) Ionic Answer: C Diff: 2 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.5 Global L.O.: G1 30) If sulfur has an atomic number of 16, how many covalent bonds can it form with other atoms? A) Zero B) Two C) Four D) Six E) Eight Answer: B Diff: 2 Chapter Section: 2.2 Skill: Application/Analysis Learning Outcome: 2.5 Global L.O.: G1 10 Copyright © 2017 Pearson Education, Inc. 31) The part of the atom that has the greatest biological interest and interactions with other atoms is the A) proton. B) electron. C) neutron. D) innermost electron shell. Answer: B Diff: 2 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.5 Global L.O.: G1 32) Which of the following pairs has the most similar chemical properties to each other? A) 1H and 22Na B) 12C and 28Si C) 16O and 32S D) 12C and 14C E) 1H and 2He Answer: D Diff: 3 Chapter Section: 2.2 Skill: Synthesis/Evaluation Learning Outcome: 2.2 Global L.O.: G1 33) A single covalent chemical bond represents the sharing of how many electrons? A) One B) Two C) Three D) Four E) Six Answer: B Diff: 2 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.5 Global L.O.: G1 11 Copyright © 2017 Pearson Education, Inc. 34) Polar molecules A) have an overall negative electric charge. B) have an equal distribution of electric charge. C) have an overall positive electric charge. D) have an unequal distribution of electric charge. E) are always ions. Answer: D Diff: 1 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 35) The hydrogen bond between two water molecules forms because water is A) polar. B) nonpolar. C) a large molecule. D) a small molecule. E) hydrophobic. Answer: A Diff: 1 Chapter Section: 2.2 Skill: Application/Analysis Learning Outcome: 2.6 Global L.O.: G1 36) Hydrogen bonding can take place between a hydrogen atom and what other atom? A) Nitrogen B) Oxygen C) Fluorine D) Hydrogen E) Nitrogen, oxygen, and fluorine Answer: B Diff: 1 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.5 Global L.O.: G1 12 Copyright © 2017 Pearson Education, Inc. 37) Which statement is an accurate description of water molecules? A) They are ionically bonded. B) They are charged and nonpolar. C) They are slightly charged and polar. D) They are uncharged and nonpolar. Answer: C Diff: 2 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 38) Which of the following is an example of hydrogen bonding? A) The bond between O and H in a single molecule of water B) The bond between O of one water molecule and H of a separate water molecule C) The bond between O of one water molecule and O of a separate water molecule D) The bond between H of one water molecule and H of a separate water molecule E) The bond between the H of a water molecule and H of a hydrogen molecule Answer: B Diff: 2 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.5 Global L.O.: G1 39) Which of the following results from a transfer of electron(s) between atoms (e.g., NaCl)? A) Nonpolar covalent bond B) Polar covalent bond C) Ionic bond D) Hydrogen bond E) Electron-proton interaction Answer: C Diff: 1 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.5 Global L.O.: G1 13 Copyright © 2017 Pearson Education, Inc. 40) Which of the following results from an unequal sharing of electrons between atoms? A) Nonpolar covalent bond B) Polar covalent bond C) Ionic bond D) Hydrogen bond E) Electron-proton interaction Answer: B Diff: 1 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.5 Global L.O.: G1 41) Which of the following best explains the attraction of water molecules to each other? A) Nonpolar covalent bond B) Polar covalent bond C) Ionic bond D) Hydrogen bond E) Electron-proton interaction Answer: D Diff: 1 Chapter Section: 2.2 Skill: Application/Analysis Learning Outcome: 2.6 Global L.O.: G1 42) Which of the following is LEAST affected by the presence of water? A) Nonpolar covalent bond B) Polar covalent bond C) Ionic bond D) Hydrogen bond E) Electron-proton interaction Answer: A Diff: 2 Chapter Section: 2.2 Skill: Application/Analysis Learning Outcome: 2.6 Global L.O.: G1 14 Copyright © 2017 Pearson Education, Inc. 43) What happens when hydrochloric acid (HCl) dissociates in pure water? A) The HCl molecules separate into H+ and Cl- ions. B) The water has a decrease of H+ ions. C) The HCl molecules float on top of the water. D) The concentration of OH- ions increases. E) The pH of the solution increases. Answer: A Diff: 2 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.7 Global L.O.: G1 44) An atom of nitrogen attracts electrons more strongly than an atom of hydrogen. In an ammonia molecule (NH3), which of the following best describes the electrical charge of the individual atoms? A) The nitrogen is slightly positive. B) The nitrogen becomes neutral. C) The nitrogen is slightly more negative. D) The hydrogens are strongly negative. E) Charges balance out and none of the atoms has any charge. Answer: C Diff: 2 Chapter Section: 2.3 Skill: Application/Analysis Learning Outcome: 2.5 Global L.O.: G1 45) If a substance measures 7 on the pH scale, that substance A) has equal concentrations of H+ and OH- ions. B) may be lemon juice. C) has a higher concentration of OH- than H+ ions. D) probably lacks OH- ions. E) is basic. Answer: A Diff: 2 Chapter Section: 2.3 Skill: Application/Analysis Learning Outcome: 2.7 Global L.O.: G1 15 Copyright © 2017 Pearson Education, Inc. 46) A neutral solution A) has no H+. B) has no OH-. C) has equal amounts of H+ and OH-. D) is hydrophobic. E) has a pH of 0. Answer: C Diff: 2 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.7 Global L.O.: G1 47) How do buffers work? A) They soak up extra acid and base. B) They accept and release H+. C) They accept and release OH-. D) They convert H+ and OH- to water. E) They monitor the blood pH. Answer: B Diff: 3 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.7 Global L.O.: G1 48) The human body must maintain a constant pH. In the blood, bicarbonate serves as a(n) ________ to help maintain the necessary pH. A) acid B) buffer C) base D) solvent Answer: B Diff: 2 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.7 Global L.O.: G1 16 Copyright © 2017 Pearson Education, Inc. 49) Milk of magnesia is often used to treat stomach upset. It has a pH of 10. Based on this information, milk of magnesia A) is a base. B) is hydrophobic. C) is an acid. D) has the same pH as stomach acid. Answer: A Diff: 2 Chapter Section: 2.3 Skill: Application/Analysis Learning Outcome: 2.7 Global L.O.: G1 50) What is meant by the statement that water has a high specific heat? A) It can absorb a lot of energy without changing temperature. B) It grows hot quickly. C) The boiling point of water is low. D) Water can heat up to only a certain temperature. E) Water freezes easily. Answer: A Diff: 3 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 51) Which of the following properties of water enable(s) it to function as a regulator of temperature for living organisms? (Hint: Think about what happens when you are sunbathing.) A) High specific heat B) Low specific heat C) High heat of vaporization D) High specific heat and high heat of vaporization E) High specific heat and low heat of vaporization Answer: E Diff: 2 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 17 Copyright © 2017 Pearson Education, Inc. 52) The fact that salt dissolves in water is best explained by the A) slightly charged nature of water molecules. B) polar nature of water molecules. C) hydrophobic nature of salt. D) ionic nature of water molecules. E) hydrophobic nature of the water. Answer: B Diff: 2 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 53) Hydrophilic molecules A) form hydrogen bonds among themselves. B) are neutral and nonpolar. C) readily dissolve in water. D) do not readily dissolve in water. E) are repelled by water. Answer: C Diff: 2 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 54) Water moves through a plant because of the property of A) high heat of fusion. B) high heat of vaporization. C) high specific heat. D) cohesion. Answer: D Diff: 2 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 18 Copyright © 2017 Pearson Education, Inc. 55) Water molecules are cohesive because they A) make up 60% to 90% of an organism’s body weight. B) form hydrogen bonds. C) contain protons. D) stick to other polar molecules. E) are repelled by nonpolar molecules. Answer: B Diff: 2 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 56) When the acidic level of human blood increases, how is the proper balance of hydrogen ions (H+) restored? A) Bicarbonate (HCO3-) releases H+ ions that combine with excess OH- ions to form H2O. B) H+ ion-donor levels increase. C) Bicarbonate (HCO3-) accepts H+ ions and forms carbonic acid. D) Carbonic acid eats up the extra OH- ions. Answer: C Diff: 2 Chapter Section: 2.3 Skill: Application/Analysis Learning Outcome: 2.7 Global L.O.: G1 57) For ice to melt, it has to A) absorb heat from its surroundings. B) become less dense. C) increase its property of cohesion. D) increase its heat of vaporization. Answer: A Diff: 2 Chapter Section: 2.3 Skill: Remembering/Understanding Learning Outcome: 2.6 Global L.O.: G1 19 Copyright © 2017 Pearson Education, Inc. 58) What determines the cohesiveness of water molecules? A) Hydrogen bonds B) Ionic bonds C) Covalent bonds D) Hydrophobic interactions Answer: A Diff: 2 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 59) If you place a paper towel in a dish of water, the water will A) separate into H+ and OH- ions, which will react with the paper towel molecules. B) dissolve the towel because water is a good solvent. C) move away from the towel because water molecules have hydrophobic interactions. D) move up the towel as the water adheres to the paper towel while the cohesive water molecules stay bound to each other. E) move up the towel because water molecules move quickly as it vaporizes. Answer: D Diff: 2 Chapter Section: 2.3 Skill: Synthesis/Evaluation Learning Outcome: 2.6 Global L.O.: G1 60) Sweating is a useful cooling mechanism for humans because water A) takes up a great deal of heat in changing from its liquid state to its gaseous state. B) takes up a great deal of heat in changing from its solid state to its liquid state. C) can exist in two states at temperatures common on Earth. D) is an outstanding solvent. E) ionizes readily. Answer: A Diff: 2 Chapter Section: 2.3 Skill: Application/Analysis Learning Outcome: 2.6 Global L.O.: G1 20 Copyright © 2017 Pearson Education, Inc. 61) In general, a substance that carries an electric charge can dissolve in water. Given this fact, which of the following would most likely NOT dissolve in water? A) Ionic compounds B) Polar covalent molecules C) Nonpolar molecules D) NaCl Answer: C Diff: 2 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 62) If you place a feather on the surface of a bowl of water, the feather remains suspended on the surface due to the A) surface tension of the water. B) fact that water is a good solvent. C) polarity of the water. D) density of the water. Answer: A Diff: 1 Chapter Section: 2.3 Skill: Application/Analysis Learning Outcome: 2.6 Global L.O.: G1 63) The specific heat of water is 10 times greater than that of iron. You place a metal pot full of water on the stove to heat it up. You touch the metal handle of the pot when the water is still only lukewarm. Which of the following best describes what happens? A) You find that the handle is cooler than the water in the pot. B) You burn your finger and pull your hand away from the hot metal handle. C) You find that both the water and the handle are the same temperature. D) You determine that metal pots full of water produce acids and bases. Answer: B Diff: 2 Chapter Section: 2.3 Skill: Application/Analysis Learning Outcome: 2.6 Global L.O.: G1; G2 21 Copyright © 2017 Pearson Education, Inc. 64) You drop a handful of common table salt into a glass of water. Which of the following best describes what is happening inside the glass at the molecular level? A) The positively charged hydrogen ends of the water molecules are attracted to sodium ions. B) The positively charged hydrogen ends of the water molecules are attracted to chloride ions. C) Sodium and chloride ions form a covalent bond. D) Water and sodium form a covalent bond. Answer: B Diff: 1 Chapter Section: 2.3 Skill: Application/Analysis Learning Outcome: 2.6 Global L.O.: G1; G2 65) Your friend does a belly flop into a swimming pool. The stinging pain he feels is most likely due to the A) surface tension of water (caused by the large number of hydrogen bonds that form between water molecules). B) fact that water is a good solvent. C) pH of the water. D) hydrophobic nature of your friend’s skin. Answer: A Diff: 1 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 66) Which of the following is the densest? A) Liquid water B) Steam C) Ice Answer: A Diff: 1 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 22 Copyright © 2017 Pearson Education, Inc. 67) Unlike a rock, a reptile can sit in the hot sunshine without its body temperature soaring quickly. This is because the water in its body A) has a high specific heat. B) has a low specific heat. C) is a good solvent. D) is a poor solvent. Answer: A Diff: 1 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 2.2 True/False Questions 1) Isotopes are atoms of the same element that have different numbers of protons. Answer: FALSE Diff: 1 Chapter Section: 2.1 Skill: Knowledge/Comprehension Learning Outcome: 2.1 Global L.O.: G1 2) Every atom of the same element has an equal number of electrons and protons. Answer: TRUE Diff: 1 Chapter Section: 2.1 Skill: Knowledge/Comprehension Learning Outcome: 2.1 Global L.O.: G1 3) Acids have pH values below 7, whereas bases have pH values above 7. Answer: TRUE Diff: 2 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.7 Global L.O.: G1 4) The attractive force that holds two or more water molecules together is an example of an ionic bond. Answer: FALSE Diff: 2 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 23 Copyright © 2017 Pearson Education, Inc. 5) When water freezes, stable hydrogen bonds form between the water molecules that create an open, six-sided (hexagonal) arrangement. Answer: TRUE Diff: 2 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 6) Water surface tension is a result of the cohesive nature of water molecules. Answer: TRUE Diff: 1 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 7) To maintain a constant pH, buffers act to either accept or release H+. Answer: TRUE Diff: 1 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.7 Global L.O.: G1 8) Most liquids become less dense upon solidification, but water is different in that it becomes denser when it solidifies. Answer: FALSE Diff: 2 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 2.3 Fill-in-the-Blank Questions 1) The chemical properties of an element are determined by the number of ________ in its outermost energy shell. Answer: electrons Diff: 2 Chapter Section: 2.1 Skill: Knowledge/Comprehension Learning Outcome: 2.2 Global L.O.: G1 24 Copyright © 2017 Pearson Education, Inc. 2) Isotopes are atoms of the same element that have different numbers of ________. Answer: neutrons Diff: 1 Chapter Section: 2.1 Skill: Knowledge/Comprehension Learning Outcome: 2.2 Global L.O.: G1 3) The second electron shell is considered to be full when it contains ________ electrons. Answer: eight Diff: 1 Chapter Section: 2.1 Skill: Knowledge/Comprehension Learning Outcome: 2.2 Global L.O.: G1 4) A basilisk lizard can run across the surface of a pond due to a property of water called ________. Answer: surface tension Diff: 2 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 5) Ions and polar molecules that are electrically attracted to water molecules are ________. Answer: hydrophilic Diff: 2 Chapter Section: 2.3 Skill: Knowledge/Comprehension Learning Outcome: 2.6 Global L.O.: G1 2.4 Short Answer Questions 1) What is the difference between covalent and ionic bonds? Answer: Covalent bonds are the sharing of electrons between atoms, whereas ionic bonds are the electric charge attraction between two ions (typically a metal and a non-metal). Diff: 2 Chapter Section: 2.2 Skill: Synthesis/Evaluation Learning Outcome: 2.2 Global L.O.: G1; G8 25 Copyright © 2017 Pearson Education, Inc. 2) more stable than a hydrogen atom (atomic number 1)? Answer: Two electrons completely fill the outermost electron shell of helium, but hydrogen must accept an electron before its outermost shell is filled. Diff: 2 Chapter Section: 2.2 Skill: Synthesis/Evaluation Learning Outcome: 2.2 Global L.O.: G1; G8 3) What type of bonding exists between the slight positive charge of a hydrogen atom and the slight negative charge of a nearby oxygen atom? Answer: hydrogen bonding Diff: 2 Chapter Section: 2.2 Skill: Knowledge/Comprehension Learning Outcome: 2.5 Global L.O.: G1; G8 4) What property of water, in which water molecules stick to each other, is responsible for the ability of plants to get water from their roots up to their leaves? Answer: cohesion Diff: 1 Chapter Section: 2.3 Skill: Application/Analysis Learning Outcome: 2.6 Global L.O.: G1; G8 5) How does a base differ from an acid? Answer: A base is a solution with a concentration of OH- that is higher than the concentration of H+ (pH greater than 7). An acid has a H+ concentration that exceeds its OH- concentration (pH less than 7). Diff: 2 Chapter Section: 2.3 Skill: Synthesis/Evaluation Learning Outcome: 2.7 Global L.O.: G1; G8 26 Copyright © 2017 Pearson Education, Inc. 6) Imagine that you are trying to make a homemade salad dressing and place several drops of olive oil into a container of water. You stir the solution, but the oil doesn’t readily mix. Instead, you observe a glistening clump of oil floating on the surface. Explain what is happening at the molecular level. (Your answer should include the term hydrophobic.) Answer: When oil molecules are together in water, their nonpolar surfaces are hydrophobic and nestle together. They are surrounded by water molecules that form hydrogen bonds with one another but not with the oil. Diff: 3 Chapter Section: 2.3 Skill: Synthesis/Evaluation Learning Outcome: 2.6 Global L.O.: G1; G8 2.5 Art Questions 1) Which of these atoms would become inert if it accepted three electrons? A) Carbon B) Oxygen C) Phosphorus D) Calcium Answer: C Diff: 2 Chapter Section: 2.2 Skill: Synthesis/Evaluation Learning Outcome: 2.2 Global L.O.: G1; G3 27 Copyright © 2017 Pearson Education, Inc. 2) Which of the following is attracted to the hydrogen “end” of a water molecule, as depicted in this figure? A) NaCl B) H C) ClD) Na+ Answer: C Diff: 1 Chapter Section: 2.3 Skill: Application/Analysis Learning Outcome: 2.6 Global L.O.: G1 28 Copyright © 2017 Pearson Education, Inc. 2.6 Scenario Questions 1) Different types of living matter often have different forms of the same elements in their bodies. For example, the nitrogen in an animal often has a slightly different atomic structure than the nitrogen in a plant. Recently, nutritionists have discovered how to deduce the diets of various animal species by examining the type of nitrogen (and other elements) inside their bodies. What is the chemical basis behind this scenario? A) Antioxidants buffer the potential damage that free radicals do to cells. B) Radioactive elements can be used to trace the paths of molecules through the body. C) Hydrophobic interactions keep water molecules from forming bonds with fats and oils. D) Isotopes of the same element have the same atomic number but different atomic masses. E) Covalent bonds result when two atoms share electrons. Answer: D Diff: 3 Chapter Section: 2.1 Skill: Application/Analysis Learning Outcome: 2.4 Global L.O.: G1; G8 2) All animals need oxygen gas (O2) for their primary cellular-level functioning. Inside the cell, O2 is split apart into oxygen atoms. Eventually, electrons that are flowing through the cell will be “received” by this oxygen. But first, the electrons combine with protons present in the cell to form a basic element that has a single proton and a single electron. Then this element combines with the oxygen to form a certain chemical compound. In this scenario, what chemical compound is produced when this element combines with oxygen? A) Water (H2O) B) Carbon dioxide (CO2) C) Ozone (O3) D) Bicarbonate (HCO3) Answer: A Diff: 3 Chapter Section: 2.1 Skill: Synthesis/Evaluation Learning Outcome: 2.2 Global L.O.: G1; G8 29 Copyright © 2017 Pearson Education, Inc.