Biology: Concepts and Connections, 5e (Campbell)
Chapter 2: The Chemical Basis of Life
1) Which one of the following statements is false about the noxious alkaloid chemical used by rattlebox moths?
A) The chemical originally comes from a plant eaten by the rattlebox moth caterpillar.
B) Only males obtain the chemical from plants.
C) During mating, males transfer to the female an extra dose of the chemical.
D) During the courtship dance, males release into the air puffs of a chemical derived from the alkaloid to help a female assess how much alkaloid he has.
E) All of the choices are true.
Answer:
Topic: Introduction
Skill: Factual Recall
2) Which one of the following is not a trace element in the human body?
A) fluorine
B) nitrogen
C) zinc
D) manganese
E) iodine
Answer:
Topic: Introduction
Skill: Factual Recall
3) The four most common elements in living organisms are
A) C, H, O, Fe.
B) C, H, O, Na.
C) C, H, O, N.
D) C, N, O, Na.
E) Fe, N, O, Ca.
Answer:
Topic: Introduction
Skill: Factual Recall
4) Matter
A) is what life is composed of.
B) occupies space.
C) has mass.
D) is composed of elements.
E) All of the choices are correct.
Answer:
Topic: Introduction
Skill: Factual Recall
5) Which one of the following is added to water in some communities to reduce tooth decay?
A) nitrogen
B) sodium
C) chlorine
D) potassium
E) fluoride
Answer:
Topic: 2.2
Skill: Factual Recall
6) Which one of the following is commonly added to table salt to prevent the formation of goiters?
A) iodine
B) iron
C) calcium
D) magnesium
E) fluoride
Answer:
Topic: 2.2
Skill: Factual Recall
7) In the equation 2 H2 + O2 ? 2 H2O,
A) H2, O2, and H2O are all compounds.
B) H2, O2, and H2O are all elements.
C) only H2O is a compound.
D) only H2 and O2 are compounds.
E) H2, O2, and H2O are all trace elements.
Answer:
Topic: 2.3
Skill: Conceptual Understanding
8) A compound
A) is a pure element.
B) is less common than a pure element.
C) contains two or more elements in a fixed ratio.
D) is exemplified by sodium.
E) is a solution.
Answer:
Topic: 2.3
Skill: Factual Recall
9) The nucleus of an atom contains
A) protons and neutrons.
B) protons and electrons.
C) only neutrons.
D) only protons.
E) only electrons.
Answer:
Topic: 2.4
Skill: Factual Recall
10) Electrons move about the nucleus of an atom in the same way that
A) insects fly around a bright lamp at night.
B) cars are parked along the sides of a street.
C) boats cross a lake.
D) people pass each other along a sidewalk.
E) birds migrate to a new winter home.
Answer:
Topic: 2.4
Skill: Conceptual Understanding
11) The sodium atom contains 11 electrons, 11 protons, and 12 neutrons. What is the mass number of sodium?
A) 0
B) 11
C) 22
D) 23
E) 34
Answer:
Topic: 2.4
Skill: Conceptual Understanding
12) The atomic number of an atom is
A) the number of protons in the atom.
B) the number of electrons in the atom.
C) the number of neutrons in the atom.
D) the number of protons, electrons, and neutrons in the atom.
E) the net electrical charge of the atom.
Answer:
Topic: 2.4
Skill: Factual Recall
13) Typically, nitrogen atoms are composed of seven electrons, seven protons, and seven neutrons. An isotope of nitrogen could
A) be positively charged.
B) be negatively charged.
C) have more than seven electrons and more than seven protons.
D) have more than seven protons.
E) have more than seven neutrons.
Answer:
Topic: 2.4
Skill: Factual Recall
14) A radioactive isotope is one that
A) is stable.
B) decays.
C) has more protons than the common variant of the element.
D) has more electrons than the common variant of the element.
E) has the same atomic mass, but a different atomic number than the common variant of the element.
Answer:
Topic: 2.4
Skill: Factual Recall
15) Which of the following statements about radioactive isotopes is/are true?
A) The nuclei of radioactive isotopes are unusually stable, but the atoms tend to lose electrons.
B) When given a choice between radioactive and nonradioactive isotopes of the same atom, living cells are more likely to incorporate the radioactive isotopes into their structures.
C) The tracers typically used for diagnosing medical problems remain radioactive in the body for a number of years, but give off very low levels of radioactive energy.
D) The energy emitted by radioactive isotopes can break chemical bonds and cause molecular damage in cells.
E) All of the choices are true.
Answer:
Topic: 2.5
Skill: Factual Recall
16) Radioactive isotopes
A) are frequently added to foods as nutritional supplements.
B) can be used in conjunction with PET scans to diagnose a patient.
C) have no effect on living tissue.
D) do not occur naturally.
E) are never incorporated into organic compounds.
Answer:
Topic: 2.5
Skill: Factual Recall
17) When full, the innermost electron shell of an atom contains __________ electrons, and the outermost shell contains __________ electrons.
A) 2 . . . 2
B) 2 . . . 8
C) 4 . . . 8
D) 8 . . . 2
E) 8 . . . 8
Answer:
Topic: 2.6
Skill: Factual Recall
18) The farther an electron is from the nucleus, the
A) greater its energy.
B) lower the atomic number.
C) more unstable the isotope.
D) more likely it is to be radioactive.
E) more inert the atom.
Answer:
Topic: 2.6
Skill: Factual Recall
19) Table salt is formed when
A) chlorine gives an electron to sodium.
B) a hydrogen bond forms between sodium and chlorine.
C) sodium and chlorine share electrons to form a bond.
D) sodium crystals combine with chlorine crystals.
E) None of the statements are true.
Answer:
Topic: 2.7
Skill: Factual Recall
20) The body uses atoms in different ways to accomplish different tasks. For example, one portion of the body's calcium supply strengthens bones, whereas another portion combines with proteins to stimulate blood clotting after tissue injury. Which of the statements below provides the most logical chemical explanation of calcium's ability to perform such different functions?
A) The bone contains calcium salts, which are less reactive than the calcium ions found in the blood.
B) The calcium in blood is a more reactive form of the atom and therefore has fewer protons than the calcium in bone.
C) There are many different isotopes of calcium, and the most reactive isotope is found in the bone.
D) The calcium in blood has a lighter atomic mass than the calcium in bone and is in a more reactive form.
E) The calcium in blood has fewer protons, is a more reactive form of the atom, and has a lighter atomic mass than the calcium in bone.
Answer:
Topic: 2.7
Skill: Application
21) Medicines are often administered in pill form. In many cases, the active ingredient of the pill (the drug) is joined to another substance by __________. This forms a(n) __________, which is stable in the dry environment of a pill bottle but dissociates under the wet conditions of the digestive system to release the drug to the body.
A) ionic bonds . . . salt
B) hydrogen bonds . . . base
C) ionic bonds . . . acid
D) covalent bonds . . . salt
E) polar covalent bonds . . . acid or base (depending on the drug)
Answer:
Topic: 2.7
Skill: Application
22) A(n) __________ forms when two atoms share electrons.
A) ion
B) element
C) covalent bond
D) ionic bond
E) hydrogen bond
Answer:
Topic: 2.8
Skill: Factual Recall
23) What is the fundamental difference between covalent and ionic bonding?
A) In a covalent bond, the partners have identical electronegativity; in an ionic bond, one of them is more electronegative.
B) In a covalent bond, the partners share a pair of electrons; in an ionic bond, one partner captures an electron from the other.
C) In covalent bonding, both partners end up with filled outer electron shells; in ionic bonding, one partner does and the other does not.
D) Covalent bonding involves only the outer electron shell; ionic bonding also involves the next inner electron shell.
E) Covalent bonds form between atoms of the same element; ionic bonds, between atoms of different elements.
Answer:
Topic: 2.8
Skill: Factual Recall
24) The oxygen atom of a water molecule
A) is more positively charged than the hydrogen atoms.
B) attracts electrons less strongly than the hydrogen atoms.
C) is more electronegative than the hydrogen atoms.
D) is electrically neutral.
E) is attracted to the negatively charged atoms of other molecules.
Answer:
Topic: 2.9
Skill: Conceptual Understanding
25) Many fabrics are coated with a "water-repellent" chemical that causes water to bead on the fabric instead of soaking in. This probably occurs because
A) the coating has positive charges that repel the positively charged ends of the water molecules.
B) the coating has negative charges that repel the negatively charged ends of the water molecules.
C) the coating is neutral, and therefore repels water, which is also neutral.
D) the coating is neutral and repels the positive and negative ends of the water molecules.
E) the coating has positive charges that repel the positively charged ends of the water molecules and also has negative charges that repel the negatively charged ends of the water molecules.
Answer:
Topic: 2.9
Skill: Application
26) A water molecule (H-O-H) is held together by
A) an ionic bond.
B) a single covalent bond.
C) a double covalent bond.
D) a polar covalent bond.
E) hydrogen bonds.
Answer:
Topic: 2.9
Skill: Factual Recall
27) The hydrogen atoms of a water molecule are bonded to the oxygen atom by __________ bonds, whereas neighboring water molecules are held together by __________ bonds.
A) hydrogen . . . ionic
B) hydrogen . . . polar covalent
C) polar covalent . . . hydrogen
D) ionic . . . covalent
E) polar covalent . . . ionic
Answer:
Topic: 2.9, 2.10
Skill: Factual Recall
28) __________ are weak bonds that are not strong enough to hold atoms together to form molecules but are strong enough to form bridges between molecules.
A) Ionic bonds
B) Covalent bonds
C) Polar covalent bonds
D) Hydrogen bonds
E) Anionic bonds
Answer:
Topic: 2.10
Skill: Factual Recall
29) Water molecules stick to other water molecules because
A) water molecules are neutral, and neutral molecules are attracted to each other.
B) hydrogen bonds form between the hydrogen atoms of one water molecule and the oxygen atoms of other water molecules.
C) covalent bonds form between the hydrogen atoms of one water molecule and the oxygen atoms of other water molecules.
D) the hydrogen atoms of adjacent water molecules are attracted to one another.
E) the oxygen atoms of adjacent water molecules are attracted to one another.
Answer:
Topic: 2.10
Skill: Conceptual Understanding
30) After turning the water off at the end of a shower, water still clings to your body because of
A) water's versatility as a solvent.
B) cohesion.
C) adhesion.
D) evaporative cooling.
E) All of the choices are correct.
Answer:
Topic: 2.11
Skill: Application
31) The ability of water molecules to form hydrogen bonds with other water molecules is critical to
A) evaporative cooling of skin surfaces.
B) the movement of water from the roots of a tree to its leaves.
C) the milder temperatures of coastal regions compared to inland areas.
D) the ability of certain insects to walk on the surface of water.
E) all of these factors.
Answer:
Topic: 2.11, 2.12
Skill: Conceptual Understanding
32) As ice melts,
A) hydrogen bonds are broken.
B) water molecules become less tightly packed.
C) the water becomes less dense.
D) covalent bonds form.
E) All of the choices are true.
Answer:
Topic: 2.12, 2.13
Skill: Conceptual Understanding
33) The temperature of evaporation is much higher for water than for alcohol. Without knowing more about the chemistry of alcohol, which of the following is the most logical chemical explanation for this phenomenon?
A) Ionic bonds form between alcohol molecules. These are the weakest type of bond and are easier to break than the hydrogen bonds between water molecules.
B) Alcohol has a higher surface tension than water. This means that alcohol molecules can easily break away from other alcohol molecules and evaporate at a lower temperature.
C) Alcohol molecules are more cohesive than water molecules. This means that as alcohol molecules evaporate, they pull other alcohol molecules into the air along with them.
D) Fewer hydrogen bonds form between alcohol molecules. As a result, less heat is needed for alcohol molecules to break away from solution and enter the air.
E) None of the choices is a logical chemical explanation for this phenomenon.
Answer:
Topic: 2.12, 2.13
Skill: Application
34) Which one of the following statements about water is false?
A) Ice is less dense than liquid water.
B) The hydrogen bonds in ice are less stable than the hydrogen bonds in liquid water.
C) Water naturally exists in all three physical states on Earth.
D) Floating ice on a pond insulates the liquid water below, slowing its rate of freezing.
E) If ice sank, the oceans would eventually freeze solid.
Answer:
Topic: 2.13
Skill: Factual Recall
35) You've made a hot drink by dissolving a teaspoon of instant coffee and a teaspoon of sugar in a cup of hot water. Which of the following is/are true?
A) You've just prepared an aqueous solution.
B) The water is the solute portion of the drink.
C) The instant coffee and sugar are solvents.
D) The instant coffee and sugar dissolve because they have no electropositive or electronegative regions to repel the electropositive and electronegative regions of the water molecules.
E) All of the choices are true.
Answer:
Topic: 2.14
Skill: Application
36) Which of the following is not related to the ability of NaCl to dissolve in water?
A) The atoms of this salt are held together by ionic bonds.
B) Water is a polar compound.
C) Hydrogen bonds between water molecules are weaker than the hydrogen bonds between sodium and water or between chloride and water.
D) Ionic bonds tend to dissociate in water.
E) Positively charged substances are attracted to negatively charged substances.
Answer:
Topic: 2.14
Skill: Conceptual Understanding
37) A solute is
A) the dissolving agent of a solution.
B) the liquid portion of a solution.
C) usually water in living cells.
D) the substance that is dissolved in solution.
E) the dissolving agent of a solution which is usually oxygen in living cells.
Answer:
Topic: 2.14
Skill: Factual Recall
38) A pharmaceutical company hires a chemist to analyze the purity of the water being used in its drug preparations. If the water is pure, the chemist would expect to find
A) only molecules of H2O.
B)H2O molecules and H+ ions.
C) H2O molecules and OH– ions.
D) H2O molecules, H+ ions, and OH– ions.
E) only H+ ions and OH– ions.
Answer:
Topic: 2.15
Skill: Conceptual Understanding
39) Bases
A) donate H+ ions to solutions.
B) accept H+ ions from solutions.
C) donate OH– ions to solutions.
D) accept OH– ions from solutions.
E) either accept H+ ions from solutions or donate OH– ions to solutions.
Answer:
Topic: 2.15
Skill: Factual Recall
40) A solution with a pH of 7 is
A) strongly acidic.
B) weakly acidic.
C) neutral.
D) weakly basic.
E) strongly basic.
Answer:
Topic: 2.15
Skill: Factual Recall
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