Biology: Concepts and Connections, 6e (Campbell)
Chapter 2
The Chemical Basis of Life
Multiple-Choice Questions
1) What phrase best describes the connection between the ants' use of formic acid and the theme of Chapter 2?
A) Ants are important for the survival of trees.
B) Ants use the trees as a home.
C) Other tree species could benefit from the ants.
D) Chemicals are part of the hierarchical structure of life.
E) Ants and trees can form symbiotic relationships.
Answer:
Topic: Opening Essay
Skill: Conceptual Understanding
2) 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: 2.1
Skill: Factual Recall
3) Which of the following is a trace element in the human body?
A) carbon
B) nitrogen
C) zinc
D) oxygen
E) hydrogen
Answer:
Topic: 2.1
Skill: Factual Recall
4) Which of the following statements regarding matter is false?
A) All life is composed of matter.
B) Matter occupies space.
C) Matter has mass.
D) Matter is composed of elements.
E) Matter can be created and destroyed.
Answer:
Topic: 2.1
Skill: Factual Recall
5) Which of the following trace elements 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
6) Which of the following trace elements may be added to bottled water in an effort to prevent tooth decay?
A) nitrogen
B) sodium
C) chlorine
D) potassium
E) fluoride
Answer:
Topic: 2.2
Skill: Factual Recall
7) Which of the following statements best describes a compound?
A) A compound is a pure element.
B) A compound is less common than a pure element.
C) A compound contains two or more different elements in a fixed ratio.
D) A compound is exemplified by sodium.
E) A compound is a solution.
Answer:
Topic: 2.3
Skill: Factual Recall
8) 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
9) Which of the following particles is found in the nucleus of an atom?
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) What is the atomic mass of an atom that has 6 protons, 6 neutrons, and 6 electrons?
A) 6
B) 8
C) +1
D) 12
E) 18
Answer:
Topic: 2.4
Skill: Factual Recall
12) An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many electrons does boron have?
A) 11
B) 15
C) 0
D) 5
E) 2
Answer:
Topic: 2.4
Skill: Application
13) Which of the following is another term used for atomic mass?
A) roberts
B) darwin
C) mendel
D) dalton
E) calvin
Answer:
Topic: 2.4
Skill: Factual Recall
14) 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
15) Which of the following best describes the atomic number of an atom?
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
16) Typically, nitrogen atoms are composed of electrons, protons, and neutrons. An isotope of nitrogen could
A) be positively charged.
B) be negatively charged.
C) have more than electrons and more than protons.
D) have more than protons.
E) have more than neutrons.
Answer:
Topic: 2.4
Skill: Factual Recall
17) A radioactive isotope is an isotope 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
18) If you found a fossilized dinosaur bone, what method could be used to determine the age of the fossil?
A) electrophoresis
B) DNA fingerprinting
C) isotope analysis
D) radial immunodiffusion
E) high-pressure liquid chromatography
Answer:
Topic: 2.4
Skill: Application
19) Which of the following statements about radioactive isotopes is 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) Radioactive elements are natural and therefore not harmful.
Answer:
Topic: 2.5
Skill: Factual Recall
20) Based on your understanding of radioactive isotopes and Alzheimer's disease, what might occur with the use of radioactive isotopes when diagnosing this brain disease?
A) It would not be very accurate.
B) It could cause more cellular damage, worsening the condition.
C) It only works on diseased brains.
D) It would only work if the isotope was stable.
E) Naturally occurring radioactive isotopes will provide accurate results.
Answer:
Topic: 2.5
Skill: Conceptual Understanding
21) Radioactive isotopes
A) are frequently added to foods as nutritional supplements.
B) can be used in conjunction with PET scans to diagnose diseases.
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
22) When full, the innermost electron shell of argon 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
23) What happens to an atom if the electrons in the outer shell are altered?
A) The atom becomes radioactive.
B) The atom will disintegrate.
C) The properties of the atom will change.
D) The atom will remain the same.
E) The atom's characteristics change and it becomes a different element.
Answer:
Topic: 2.6
Skill: Factual Recall
24) Which particles increase by one as we move from left to right in the elements on the periodic table?
A) neutrons only
B) neutrons and protons
C) electrons only
D) electrons and protons
E) electrons and neutrons
Answer:
Topic: 2.6
Skill: Factual Recall
25) 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) sodium donates its single outer electron to chlorine
Answer:
Topic: 2.7
Skill: Factual Recall
26) 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
27) 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
28) 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
29) A hydrogen atom has one electron. How many covalent bonds can hydrogen form?
A) one covalent bond
B) four covalent bonds
C) four covalent bonds
D) two ionic bonds
E) two isotonic bonds
Answer:
Topic: 2.8
Skill: Application
30) 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 accepts electrons 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 outermost electron shell; ionic bonding also involves the next electron shell inside
the outermost shell.
E) Covalent bonds form between atoms of the same element; ionic bonds form between atoms of different elements.
Answer:
Topic: 2.8
Skill: Conceptual Understanding
31) Which of the following statements regarding the oxygen atom of a water molecule is true?
A) Oxygen is more positively charged than the hydrogen atoms.
B) Oxygen attracts electrons less strongly than the hydrogen atoms.
C) Oxygen is more electronegative than the hydrogen atoms.
D) Oxygen is electrically neutral.
E) Oxygen is attracted to the negatively charged atoms of other molecules.
Answer:
Topic: 2.9
Skill: Conceptual Understanding
32) In a water molecule, hydrogen and oxygen are held together by a(n) ________ bond.
A) double covalent
B) ionic
C) nonpolar covalent
D) hydrogen
E) polar covalent
Answer:
Topic: 2.9
Skill: Factual Recall
33) A person shakes up vinegar and oil dressing before pouring it on salads. What is the chemical reason for doing this?
A) Vinegar contains charged water molecules, while oil is neutral and repels water.
B) Vinegar and oil must be mixed to decease the viscosity.
C) Vinegar and oil are oppositely charged, and opposites attract.
D) Oil is composed of fatty acids, which are too large to dissolve in water.
E) Vinegar has a basic pH and is neutralized when mixed with oil.
Answer:
Topic: 2.9
Skill: Application
34) 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) two polar covalent bonds.
E) hydrogen bonds.
Answer:
Topic: 2.9
Skill: Factual Recall
35) 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
36) ________ are weak bonds that are not strong enough to hold atoms together to form molecules but are strong enough to form bonds within and around large molecules.
A) Ionic bonds
B) Covalent bonds
C) Polar covalent bonds
D) Hydrogen bonds
E) Anionic bonds
Answer:
Topic: 2.10
Skill: Factual Recall
37) 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
38) The tendency of water molecules to stick together is referred to as
A) adhesion.
B) polarity.
C) cohesion.
D) transpiration.
E) evaporation.
Answer:
Topic: 2.11
Skill: Factual Recall
39) Which of the following is dependent on the ability of water molecules to form hydrogen bonds with other molecules besides water?
A) the 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) the universality of water as a solvent
Answer:
Topic: 2.11, 2.12
Skill: Conceptual Understanding
40) Water's surface tension and heat storage capacity is accounted for by its
A) orbitals.
B) weight.
C) hydrogen bonds.
D) mass.
E) size.
Answer:
Topic: 2.11, 2.12
Skill: Conceptual Understanding
41) 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) heat is released.
Answer:
Topic: 2.12, 2.13
Skill: Conceptual Understanding
Quick Reply
