THE METRIC SYSTEM AND MICROSCOPES
Definitions
Multiple Choice
__ 1. Each of the following is a compound except:
a) sodium chloride
b) carbon dioxide
c) glucose
d) hydrogen gas
e) a nucleotide
__ 2. A molecule is:
a) a combination of two or more atoms
b) less stable than its constituent atoms separated.
c) electrically charge
d) a carrier of one or more extra neutrons
e) none of the above
__ 3. What is the difference between a molecule and a compound?
a) a compound is composed of two or more atoms; a molecule is not
b) a compound has two different atoms; a molecule cannot have two different atoms
c) a molecule is charged; a compound is not
d) a compound has two or more different atoms; a molecule is composed of two or more atoms
e) a compound does not contain electrons; molecule do
__ 4. Water is an example of a(n):
a) atom
b) ion
c) compound
d) mixture
e) element
__ 5. Which of the following includes the other three?
a) an atom
b) a molecule
c) a compound
d) an element
__ 6. The smallest unit of mater which cannot be further divided by chemical means is called a(n):
a) isotope
b) molecule
c) atom
d) element
e) proton
__ 7. The smallest part of a compound that still retains the properties of the compound is called
a(n):
a) isotope
b) molecule
c) proton
d) atom
e) ion
__ 8. Which of the following is the SMALLEST unit of a chemical ELEMENT that still retains the
property of that element?
a) compound
b) proton
c) atom
d) neutron
e) electron
__ 9. Which one of the following is NOT a CHEMICAL ELEMENT?
a) carbon
b) hydrogen
c) nitrogen
d) oxygen
e) water
__ 10. Which of the following is not an element?
a) water
b) oxygen
c) carbon
d) chlorine
e) hydrogen
__ 11. Each element is unique and different from other elements because of its:
a) atomic weight
b) atomic number
c) mass number
d) atomic weight and atomic number
e) atomic weight, atomic number, and mass number
__ 12. Which statement is NOT true about elements?
a) An element cannot be broken down into substances with different properties.
b) An element consists of atoms and molecules.
c) There is only one kind of atom in each type of element.
d) All atoms of an element contain the same number of protons.
e) Atoms of an element may contain different numbers of neutrons.
__ 13. Which term is based on the Greek root word for "uncut" or "indivisible"?
a) atom
b) element
c) molecule
d) chemical
e) electron
__ 14. Anything that takes up space and has mass is matter.
a) True
b) False
__ 15. Which term is based on the Latin root word for "mass"?
a) atom
b) element
c) molecule
d) chemical
e) electron
__ 16. There are _____ naturally occurring elements.
a) 57
b) 108
c) 95
d) 92
e) 87
__ 17. Which pair has similar chemical properties?
a) 1H and 22Na
b) 12C and 28Si
c) 16O and 32S
d) 12C and 14C
e) 1H and 2He
__ 18. Phosphorus has an atomic number of 15, so what will be the distribution of its electrons?
a) The first energy level will have 8 and the second will have 7.
b) The first energy level will have 2, the second will have 8, and the third will have 5.
c) The first energy level will have 2 and the second will have 13.
d) The first, second, and third energy levels will each have 5 electrons.
e) Electron arrangement can not be determined from the atomic number.
__ 19. Which of the following is/are an atom, an isotope and an ion?
a) H+
b) 2H or deuterium
c) 3H or tritium
d) H2 or hydrogen gas
e) All of the choices are atoms, isotopes and ions.
__ 20. From the above table of radioisotopes and their properties, it is obvious that
a) the longer the half-life, the more energy emitted by the particles.
b) the longer the half-life, the less energy emitted by the particles.
c) radioisotopes of the same element must emit the same amount of energy in their emissions and decay at
the same rate.
d) adjusted for time, radioisotopes emit the same amount of energy in their emissions.
e) energy and half-life are not directly related.
__ 21. Which statement is NOT true about subatomic particles?
a) Protons are found in the nucleus.
b) Neutrons have no electrical charge.
c) Electrons contain much less mass than neutrons.
d) Electrons are found in orbitals around the nucleus.
e) All electrons in an atom contain the same amount of energy.
__ 22. Which is not true?
a) Protons carry a positive charge.
b) Electrons carry a negative charge.
c) In an atom, the number of protons and neutrons must be equal.
d) An atom is neutral when the positive and negative charges balance.
e) An ion contains one or more positive or negative charges.
__ 23. An atom's atomic number is best described as the number of
a) protons it contains.
b) neutrons it contains.
c) electrons in the outermost shell.
d) protons and neutrons it contains.
e) protons and electrons it contains.
__ 24. An atom's atomic mass is best described as the mass of
a) the protons it contains.
b) the neutrons it contains.
c) electrons in the outermost shell.
d) protons and neutrons it contains.
e) protons and electrons it contains.
__ 25. A research article indicates that researchers have used an isotope 3H to trace a certain
metabolic process. 2H contains one protein, therefore, from the symbol that is given, we
know this is a hydrogen isotope with
a) three protons.
b) three neutrons.
c) three electrons.
d) one proton and two neutrons.
e) two protons and one neutron.
__ 26. Both 18O and 16O are found in nature. However, 16O is the most common. Therefore,
a) these are different elements.
b) oxygen atoms can have eight or 10 neutrons.
c) 18O has two additional electrons in its outer shell.
d) 18O is the form of oxygen that provides living cells with life.
e) only the common form of 16O can bond with hydrogens to form H2O.
__ 27. To determine the age of fairly recent fossils and organic artifacts, it is possible to analyze
the amounts of the isotopes 14C and 14N, because over time the 14C–which originated in the
atmosphere–breaks down into 14N. What net change occurred for this to happen?
a) The 14C lost an electron.
b) The 14C gained an electron.
c) The 14C lost a proton.
d) The 14C gained a proton.
e) The 14C gained a neutron.
__ 28. An atom's nucleus is composed of:
a) protons
b) neutrons
c) protons and electrons
d) protons and neutrons
e) neutrons and electrons
__ 29. A substance with specific properties that can not be broken down or converted to another
substance is a(n):
a) element
b) molecule
c) ion
d) compound
e) mixture
__ 30. If you examined the universe, the Earth, and the human body, which of the following
combinations of elements would you find most common?
a) C, O, Na, He, P, S
b) C, Na, O, N, H, Mg
c) Cl, Ca, C, H, O, P
d) K, H, C, S, O, P
e) S, P, O, N, H, C
__ 31. Sodium (Na), atomic number 11, has a tendency to lose an electron in the presence of
chlorine. After losing the electron, Na will have _____ protons in its nucleus.
a) 10
b) 11
c) 12
d) 21
e) 22
__ 32. How many molecules of glycerol C3H8O3 would be present in 1 liter of a 1-M glycerol
solution?
a) 1
b) 14
c) 92
d) 1 x 10-7
e) 6.02 x 1025
__ 33. A measure of the average kinetic energy of the molecules in a body of matter.
a) calorie
b) temperature
c) heat of vaporization
d) buffer
e) mole
__ 34. The number of grams of a substance that equals its molecular mass in daltons.
a) calorie
b) temperature
c) heat of vaporization
d) buffer
e) mole
True – False
__ 35. Energy is anything that occupies space and has weight.
a) True
b) False
__ 36. Matter exists as a solid, liquid, or gas.
a) True
b) False
__ 37. A molecule must contain more than one atom of more than one element.
a) True
b) False
__ 38. An element is the fundamental structural unit of matter.
a) True
b) False
Short Answer
__ 39. What is the difference between an atom and an element?
Essay
Atomic Structure
Multiple Choice
__ 40. What term is based on the Greek root words for "equal" and "part"?
a) isotope
b) isomer
c) homomolecules
d) homotope
e) hydrophilic
__ 41. All atoms of an element have the same number of:
a) ions
b) protons
c) neutrons
d) electrons
e) protons and neutrons
__ 42. A(n) ________ is the smallest portion of a substance that retains the properties of an
element.
a) atom
b) compound
c) ion
d) molecule
e) mixture
__ 43. An atomic form of an element containing different numbers of neutrons is:
a) an isotope
b) an ion
c) a polar atom
d) an isomer
e) radioactive
__ 44. The negative subatomic particle is the:
a) neutron
b) proton
c) electron
d) both A and B
e) none of the above
__ 45. The positive subatomic particle is the:
a) neutron
b) proton
c) electron
d) both A and B
e) none of the above
__ 46. The neutral subatomic particle is the:
a) neutron
b) proton
c) electron
d) both A and B
e) none of the above
__ 47. The nucleus of an atom contains:
a) neutrons and protons
b) neutrons and electrons
c) protons and electrons
d) neutrons only
e) none of the above
__ 48. All ATOMS have a net (overall) ELECTRICAL CHARGE of ZERO, because all have equal
numbers of:
a) protons and electrons
b) protons and neutrons in the atomic nucleus
c) protons and electrons in the atomic nucleus
d) orbitals (shells) surrounding the atomic nucleus
e) electrons and protons in the orbitals
__ 49. Atoms of one element differ from atoms of all other elements by the numbers of _____
present.
a) protons and electrons
b) ions and protons
c) electrons and ions
d) electrons and elements
e) elements and protons
__ 50. When attempting to visualize the STRUCTURE OF AN ATOM, one can picture the TOTAL
NUMBER OF ELECTRONS surrounding the nucleus if one knows the:
a) atomic mass
b) total number of protons
c) number of orbitals (shells) present
d) overall charge of the atom
e) diameter of the nucleus
__ 51. All ATOMS have a net electrical charge of:
a) one
b) two
c) three
d) four
e) zero
__ 52. Which of the following statements about ATOMS is INCORRECT?
a) all have an atomic nucleus and at least one electron
b) all contain protons and electrons
c) each atom has the same number of protons and electrons
d) all are either positively or negatively charged
e) all have at least one shell surrounding the nucleus
__ 53. Nitrogen (atomic number = 7) has ____ electrons in its innermost shell and ____ electrons
in its outer shell.
a) 7, 0
b) 5, 2
c) 2, 5
d) 3, 4
e) 3 1/2, 3 1/2
__ 54. The atomic number of each atom is given at left. Which of the atoms has the same
number of electrons in its outer shell as carbon?
a) 7 nitrogen
b) 9 flourine
c) 10 neon
d) 12 magnesium
e) 14 silicon
__ 55. How many electrons would be expected in the outer shell of an atom with an atomic
number 17?
a) 2
b) 5
c) 7
d) 8
e) 17
__ 56. All of the following statements about electrons are true EXCEPT that:
a) they are found in the nucleus.
b) they have one unit of negative charge.
c) they weigh 1/1,840 of the weight of a proton.
d) their number equals the number of protons in the atom.
e) it is impossible to pinpoint the position of an electron at any given instant.
__ 57. Which of the following statements best describes the neutron?
a) It is about equal in mass to the proton, but opposite in charge.
b) It is about equal in mass to the electron, but opposite in charge.
c) It is about equal in mass to the proton, but not charged.
d) It is about equal in mass to the electron, but not charged.
e) It is found in shells around the nucleus.
__ 58. Oxygen has an atomic number of 8. Therefore, it must have
a) 8 protons
b) 8 electrons
c) 8 neutrons
d) only A and B are correct
e) A, B, and C are correct.
__ 59. Magnesium, which has 12 protons, has ____________ electrons in its third energy level.
a) two
b) three
c) four
d) eight
e) ten
__ 60. Magnesium, which has 12 protons, has ____________ electrons in its second energy level.
a) two
b) three
c) four
d) eight
e) ten
__ 61. The valence of an atom with 7 electrons in its outer electron shell.
a) 1
b) 2
c) 3
d) 4
e) 5
__ 62. The number of protons in an atom with the atomic number of 5.
a) 1
b) 2
c) 3
d) 4
e) 5
__ 63. The atomic number of each atom is given at left. Which of the atoms has the same valence
as carbon?
a) 7 nitrogen
b) 9 fluorine
c) 10 neon
d) 12 magnesium
e) 14 silicon
__ 64. From its atomic number of 15, it is possible to predict that the phosphorus atom has
a) 15 neutrons.
b) 15 protons.
c) 15 electrons.
d) 15 protons and 15 electrons.
e) 15 neutrons, 15 protons, and 15 electrons.
__ 65. The atomic mass of an element can be easily approximated by adding together the number
of
a) protons and neutrons.
b) electron orbitals in each energy level.
c) protons and electrons.
d) neutrons and electrons.
e) isotopes of the atom.
__ 66. Oxygen has an atomic number of 8. Therefore, it must have
1. 8 protons
2. 8 electrons
3. 8 neutrons
a) 1
b) 2
c) 3
d) Only 1 and 2 are correct.
e) 1, 2, and 3 are correct.
__ 67. The atomic number of carbon is 6. 14C is heavier than 12C because 14C has
a) six protons
b) six neutrons
c) eight protons
d) eight neutrons
e) fourteen electrons
__ 68. How do isotopes differ from each other?
a) number of protons
b) number of electrons
c) number of neutrons
d) valence electron distribution
e) ability to form ions
__ 69. Which of the following elements would be more reactive with other elements?
a) boron, #5
b) neon, #10
c) argon, #18
d) helium, #2
__ 70. The characteristic way in which atoms of an element react is most related to the
a) number of electrons in the outermost shell.
b) number of electrons in the innermost shell.
c) number of neutrons in the nucleus.
d) size of the nucleus.
__ 71. Which of the following statements is NOT true about electron configurations?
a) If an atom has only one shell, it is complete with two electrons.
b) If an atom has two or more shells, the octet rule applies.
c) If an atom has two or more shells, the outer shell is complete with eight electrons.
d) Atoms with more than eight electrons in the outer shell react by gaining electrons.
e) Atoms with eight electrons in the outer shell are not reactive at all.
__ 72. An orbital is best described as
a) the electron shell closest to the nucleus.
b) the outermost electron shell of an atom.
c) the volume of space in which electrons are most often found.
d) the original energy level of electrons in photosynthesis.
__ 73. What determines the atomic number of an atom?
a) Number of electrons in the outermost energy level.
b) Total number of energy shells.
c) Arrangement of neutrons in the atomic nucleus.
d) Number of protons in the atomic nucleus.
e) The total number of electrons and neutrons.
__ 74. The subatomic particle of an atom that carries no charge is a (an)
a) electron
b) proton
c) neutron
d) anion
e) cation
__ 75. Isotopes of an element
a) may or may not be radioactive
b) have the same atomic number but differing atomic masses
c) may be used for human disease diagnostics
d) All of the choices are correct.
True – False
__ 76. Radioactive atoms have different atomic weights than non-radioactive atoms of the same
element.
a) True
b) False
__ 77. Isotopes of an element contain the same number of protons and different numbers of
electrons.
a) True
b) False
__ 78. Isotopes of an element contain the same number of protons and different numbers of
neutrons
a) True
b) False
__ 79. Most isotopes are stable, but some are unstable and break apart, releasing radiation.
a) True
b) False
__ 80. Electrons in different electron shells contain more energy if they are further from the
nucleus.
a) True
b) False
__ 81. Isotopes are atoms of the same element that vary in the number of protons.
a) True
b) False
__ 82. Each atom has an equal number of electrons and protons.
a) True
b) False
Short Answer
__ 83. The chemical properties of an element are determined by the number of _____________ its
atoms contain.
__ 84. An isotope is atoms of the same element that have different numbers of
________________.
__ 85. The second electron shell is considered to be full when it contains ________________
electrons.
__ 86. The atomic number is based on the number of __________ in the nucleus of the atom.
Essay
Periodic table
Multiple Choice
True – False
Short Answer
Essay
Bonds -- Ionic
Multiple Choice
__ 87. The electrical attraction between oppositely charged particles results in:
a) covalent bonds
b) hydrogen bonds
c) ionic bonds
d) hydrophobic bonds
e) van der Waals interactions
__ 88. What results from the chemical reaction illustrated below?
a) isotopes
b) ions
c) a covalent bond
d) a hydrogen bond
e) hydrophobic interactions
__ 89. Results from a transfer of electron(s) between atoms.
a) nonpolar covalent molecule
b) polar covalent bond
c) ionic bond
d) hydrogen bond
e) hydrophobic interaction
__ 90. In order to fill its outermost electron energy level, chlorine needs to gain one electron and
potassium needs to lose one electron. What kind of bond do potassium and chlorine form?
a) Polar bond
b) Ionic bond
c) Peptide bond
d) Covalent bond
e) Hydrogen bond
__ 91. The ionic bond of sodium chloride is formed when
a) chlorine gains an electron from sodium.
b) sodium and chlorine share an electron pair.
c) sodium and chlorine both lose electrons from their outer energy levels.
d) sodium gains and electron from chlorine.
e) chlorine gains a proton from sodium.
__ 92. Magnesium has the atomic number of 12. What kind of bonds does it form with chlorine
(atomic number 17) and what is the formula for magnesium chloride.
a) covalent, MgCl
b)
ionic, MgCl2
c) covalent, Mg2Cl
d) ionic, MgCl
e) ionic, ClMg
__ 93. Which statement is NOT true about ionic bonds?
a) One atom acts as an electron donor and another acts as an electron acceptor.
b) Electrons are completely lost or gained in ion formation.
c) An ion has the same number of electrons as a nonionic atom of the same element.
d) An ionic reaction occurs between positive ions and negative ions.
e) A salt such as NaCl is formed by an ionic reaction.
__ 94. How does one explain the formation of ions?
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
__ 95. The formation of sodium chloride (NaCl) is the result of:
a) Covalent bonding
b) Chemical unreactivity
c) Attraction between opposite charges
d) The lack of chemical attraction
e) Both a and c
__ 96. The ionic bond of sodium chloride is formed when:
a) chlorine gains an electron from sodium
b) sodium and chlorine share an electron pair
c) sodium and chlorine both lose electrons from their outer energy levels
d) sodium gains an electron from chlorine
e) chlorine gains a proton from sodium
__ 97. What bonds are easily disrupted in aqueous solutions?
a) covalent
b) polar covalent
c) ionic
d) only covalent and polar covalent
e) covalent, polar covalent and ionic
__ 98. Magnesium has the atomic number of 12. What kind of bonds does it form with chlorine
(atomic number 17) and what is the formula?
a) covalent, MgCl
b) ionic, MgC2
c) covalent, Mg2Cl
d) ionic, MgCl
e) ionic, ClMg
__ 99. The bond in table salt (NaCl) is:
a) polar
b) ionic
c) covalent
d) double
e) nonpolar
__ 100. What TYPE OF BOND holds sodium and chlorine atoms together to form table salt?
a) ionic;
b) hydrogen;
c) molecular;
d) covalent;
e) municipal.
__ 101. If you know that an element characteristically forms IONIC BONDS and that element has
SEVEN electrons in its outer orbital (shell), it will probably:
a) lose electrons and become negatively charged
b) gain electrons and become positively charged
c) gain electrons and become negatively charged
d) lose electrons and become positively charged
e) all of these answers are correct
__ 102. A(n) _____________ forms when an atom loses or gains an electron.
a) mole
b) ion
c) molecule
d) bond
e) reaction
__ 103. What is formed when an atom either gains or loses an electron in its outer orbital (shell)?
a) molecule
b) element
c) bond
d) ion
e) reaction
__ 104. Which of the following statements about atoms that form IONS is INCORRECT?
a) all will either or lose electrons from the outermost shell
b) all will share electrons in their outer shell with adjacent atoms
c) when one electron is lost, they become positively charged
d) when one electron is gained, they become negatively charged
e) can exist with unequal numbers of protons and electrons
__ 105. What TYPE of CHEMICAL BOND is an association between two oppositely charged atoms
where one of those atoms has lost one or more electrons and the other atom has gained
one or more electrons:
a) hydrogen
b) ionic
c) municipal
d) covalent
e) hydrophobic
__ 106. What TYPE of CHEMICAL BOND is merely an ELECTROSTATIC ASSOCIATION between to
adjacent but oppositely charged atoms that have gained or lost electrons in their outer shell?
a) covalent
b) hydrophobic
c) ionic
d) municipal
e) hydrogen
__ 107. What bonds does heating easily disrupt?
a) covalent
b) polar covalent
c) ionic
d) Only B and C
e) A, B, and C are correct
__ 108. Atoms or molecules which have gained or lost electrons are termed:
a) Acids
b) Bases
c) Polymers
d) Ions
e) Buffers
True – False
Short Answer
__ 109. In an atom of an element, __________ have a negative charge, __________ have a
positive charge and __________ have a neutral charge.
__ 110. Draw the dot configuration of the molecule that would result if chlorine (17 protons)
reacted with sodium (11 protons). What type of bond would this be?
__ 111. Draw the dot configuration of the molecule that would result if magnesium (12 protons)
reacted with two fluorine atoms (9 protons). What type of bond would this be?
__ 112. Describe an ionic bond and tell where these bonds would be important in living systems.
Essay
Bonds -- Covalent
Multiple Choice
__ 113. Which of the following is true?
a) triple bonds are stronger than double bonds; double bonds are stronger than single bonds.
b) triple bonds are weaker than double bonds; double bonds are weaker than single bonds.
c) carbon bonds are stronger than other bonds; hydrogen bonds are always weakest.
d) carbon varies widely in the number of bonds it forms.
__ 114. Which of the following is a polar covalent bond?
a) H-H
b) C-C
c) H-O
d) C-H
e) O-O
__ 115. A covalent bond is likely to be polar when:
a) one of the atoms sharing electrons is much more electronegative than the other atom.
b) the two atoms sharing electrons are the same element.
c) the two atoms sharing electrons are equally electronegative.
d) it is between two atoms that are both very strong electron acceptors.
e) it joins a carbon atom to a hydrogen atom.
__ 116. Which statement is NOT true about covalent bonds?
a) Covalent bonds form when an electron is completely lost or gained from an atom.
b) A covalent molecule contains one or more covalent bonds.
c) A single covalent bond is drawn as a line between two atoms.
d) A pair of electrons is shared between two atoms for each covalent bond.
e) Shared electrons allow an atom to complete its outer electron shell in a covalent molecule.
__ 117. A bond where two adjacent atoms are SHARING one or more pair of electrons is called:
a) hydrophobic
b) municipal
c) hydrogen
d) covalent
e) ionic
__ 118. A covalent bond is likely to be polar when:
a) one of the atoms sharing electrons is much more electronegative than the other atom.
b) the two atoms sharing electrons are equally electronegative.
c) the two atoms sharing electrons are of the same element.
d) it is between two atoms that are both very strong electron acceptors.
e) it joins a carbon atom to a hydrogen atom.
__ 119. Which of the following is a polar covalent bond?
a) H-H
b) C-C
c) H-O
d) C-H
e) O-O
__ 120. What is the maximum number of covalent bonds an element with atomic number 15 can
make with hydrogen?
a) 1
b) 2
c) 3
d) 4
e) 0
__ 121. A single covalent chemical bond represents the sharing of how many electrons?
a) 1
b) 2
c) 3
d) 4
e) 6
__ 122. What is the maximum number of covalent bonds an element with atomic number 15 can
make with hydrogen?
a) 1
b) 2
c) 3
d) 4
e) 0
__ 123. What do atoms form when they share electron pairs?
a) elements
b) ions
c) aggregates
d) isotopes
e) molecules
__ 124. Results from an unequal sharing of electrons between atoms.
a) nonpolar covalent molecule
b) polar covalent bond
c) ionic bond
d) hydrogen bond
e) hydrophobic interaction
__ 125. A covalent chemical bond is one in which:
a) electrons are removed from one atom and transferred to another atom so that the two atoms become
oppositely charged.
b) protons or neutrons are shared by two atoms so as to satisfy the requirements of both.
c) outer shell electrons are shared by two atoms so as to satisfactorily fill the outer electron shells of both.
d) outer shell electrons on one atom are transferred to the inner electron shells of another atom.
e) the inner shell electrons of one atom are transferred to the outer shell of another atom.
__ 126. If sulfur has an atomic number of 16, how many covalent bonds does it form?
a) 0
b) 2
c) 4
d) 6
e) 8
__ 127. 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 ions.
__ 128. Which statement is NOT true about polar covalent bonds?
a) Most covalent bonds are nonpolar, with electrons shared fairly equally between the atoms.
b) Polar covalent bonds are important in the characteristics of water.
c) Electrons are shared unequally in a polar covalent bond.
d) The larger atom in a polar bond attracts the electron more strongly than the smaller atom.
e) The oxygen of a water molecule is electropositive relative to the hydrogen.
__ 129. 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 base are combined.
e) atoms from two molecules are attracted to each other.
__ 130. Which of these bonds is characterized by equal sharing of electrons?
a) C-H
b) O-H
c) H-Cl
d) C=O
e) N-H
__ 131. Which of the following represents a molecule characterized by polar covalent bonding?
a) NaCl
b) H2
c) H2O
d) C-C
e) CH4
__ 132. What is the maximum number of covalent bonds an element with an atomic number of 16
can make with hydrogen atoms (each with an atomic number of 1)?
a) 1
b) 2
c) 3
d) 4
e) 5
__ 133. An atom of nitrogen attracts electrons more strongly than an atom of hydrogen. Which of
the following BEST describes ammonia (NH3)?
a) The nitrogen is more slightly positive.
b) The nitrogen is strongly negative.
c) The hydrogens are more slightly positive.
d) The hydrogens are strongly negative.
e) Charges balance out and none of the atoms has any charge.
__ 134. Which of the structures below has an impossible covalent bond?
A.
D..
H
H
H
N O H
H
C
H
C
O
H
H
H
H
H
C
H
O
True – False
Short Answer
__ 135. Draw the dot configuration of the molecule that would result if two oxygen (16 protons)
reacted with each other. What type of bond would this be?
__ 136. Draw the dot configuration of the molecule that would result if oxygen (16 protons)
reacted with two hydrogen atoms (1 proton). What type of bond would this be?
__ 137. Describe a single covalent bond. Discuss why a double or a triple bond would be stronger
than the single bond.
__ 138. Describe a polar covalent bond, and explain how it is significant in living systems.
Essay
Bonds – Hydrogen Bonds
Multiple Choice
__ 139. Water is a polar solvent having both positively charged and negatively charged regions.
This polarity is caused by more _____________ on one end of the molecule than the other
ends.
a) neutrons;
b) protons;
c) ions;
d) electrons;
e) atoms.
__ 140. The partial negative charge at one end of a water molecule is attracted to the partial
positive charge of another water molecule. What is this attraction called?
a) a covalent bond
b) a hydrogen bond
c) an ionic bond
d) a hydration shell
e) a hydrophobic bond
__ 141. Which of the following is an example of a hydrogen bond?
a) the bond between C and H in methane
b) the attraction between the H of one water molecule and the O of another water molecule
c) the bond between Na and Cl in salt
d) the bond between two hydrogen atoms
e) the bond between Mg and Cl in MgCl2
__ 142. All of the following are true statements concerning hydrogen bonding
a) In H-bonds, the hydrogen atom is also involved in a polar covalent bond.
b) H-bonds are responsible for the cohesive properties of water.
c) H-bonds are among the strongest of all chemical bonds.
d) H-bonds are rapidly formed and rapidly broken.
e) Large numbers of H-bonds confer considerable stability to a group of molecules.
__ 143. ____________(s) often form as a result of polar bonds.
a) Ionic bonds
b) Hydrogen bonds
c) Peptide bonds
d) Ice
e) Water
__ 144. What determines the cohesiveness of water molecules?
a) hydrogen bonds
b) ionic bonds
c) covalent bonds
d) hydrophobic interactions
e) all of the above are correct
__ 145. The hydrogen bond between two water molecules arises because water is
a) polar.
b) nonpolar.
c) a liquid.
d) a small molecule.
e) hydrophobic.
__ 146. 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 second water molecule.
c) The bond between O of one water molecule and O of a second water molecule.
d) The bond between H of one water molecule and H of a second water molecule.
e) The bond between the H of a water molecule and the H of a hydrogen molecule.
__ 147. What is meant by saying water has a high specific heat?
a) It can absorb a lot of energy without changing temperature.
b) It grows hot very quickly.
c) The boiling point of water is very low.
d) Water can only heat up to a certain temperature.
e) Water freezes easily.
__ 148. Which property (or properties) of water enables water to function as a moderator of
temperature for living organisms?
a) high specific heat
b) high heat of vaporization
c) high heat of fusion
d) high surface tension
e) high density
__ 149. 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) adhesion
e) cohesion
__ 150. Why are water molecules cohesive?
a) Because they create surface tension
b) Because they form hydrogen bonds
c) Because they contain hydrogen
d) Because they stick to other polar molecules
e) Because they are repelled by nonpolar molecules
__ 151. What bond(s) is(are) easily disrupted in aqueous (water) solutions?
a) covalent
b) polar covalent
c) ionic
d) a and b are correct
e) a, b, and c are correct
__ 152. As ice melts, it:
a) Absorbs heat from its surroundings
b) Becomes less dense
c) Increases its property of cohesion
d) Increases its heat of vaporization
__ 153. Which statement is NOT true about water's properties?
a) Water molecules are cohesive, able to cling to each other.
b) Water molecules are adhesive, able to wet substances other than water.
c) Water is a universal solvent due to its polar nature.
d) The temperature of water rises and falls very quickly.
e) Ice is less dense than water and floats on its surface.
__ 154. All of the following are true statements concerning hydrogen bonding EXCEPT:
a) In H bonds, the hydrogen atom is also involved in a polar covalent bond.
b) H bonds are responsible for the cohesive properties of water.
c) H bonds are among the strongest of all chemical bonds.
d) H bonds are easily broken.
e) Large numbers of H bonds confer considerable stability to a group of molecules.
__ 155. Because oxygen has a stronger attraction for electrons than hydrogen does, water
molecules:
a) are nonpolar.
b) form hydrogen bonds.
c) dissolve lipid molecules
d) fail to dissolve ionic compounds
__ 156. Hydrogen bonds are important in determining the quaternary structure of proteins.
a) True
b) False
__ 157. The partial negative charge at one end of a water molecule is attracted to the partial
positive charge of another water molecule. What is this attraction called?
a) a covalent bond
b) a hydrogen bond
c) an ionic bond
d) a hydration shell
e) a hydrophobic bond
__ 158. Which of the following is an example of a hydrogen bond?
a) the bond between C and H in methane
b) the attraction between he H of one water molecule and the O of another water molecule.
c) the bond between Na and Cl in salt
d) the bond between two hydrogen atoms
e) the bond between Mg and Cl in MgCl2
__ 159. Nitrogen is much more electronegative than hydrogen (H). Which of the following
statements is correct about ammonia (NH3)?
a) Each hydrogen atom has a partial positive charge.
b) The nitrogen atom has a strong positive charge.
c) Each hydrogen atom has a slight negative charge.
d) The nitrogen atom has a partial positive charge.
e) There are covalent bonds between the hydrogen atoms.
__ 160. Best explains attraction of water molecules to each other.
a) nonpolar covalent molecule
b) polar covalent bond
c) ionic bond
d) hydrogen bond
e) hydrophobic interaction
__ 161. Nitrogen (N) is much more electronegative than hydrogen (H). Which of the following
statements is correct about ammonia (NH3)?
a) Each hydrogen atom has a partial positive charge.
b) The nitrogen atom has a strong positive charge.
c) Each hydrogen atom has a slight negative charge.
d) The nitrogen atom has a partial positive charge.
e) There are covalent bonds between the hydrogen atoms.
__ 162. A hydrogen bond is:
a) a sharing of a pair of electrons between a hydrogen and an oxygen nucleus.
b) a sharing of a pair of electrons between a hydrogen nucleus and either an oxygen or a nitrogen nucleus/
c) an attractive force that involves a hydrogen atom and an oxygen or a nitrogen atom that are either in two
different molecules are within the same molecule
d) all of the above
e) none of the above
__ 163. HYDROGEN BONDS can accurately be described as:
a) the sharing of electrons in the outer shells of two adjacent atoms
b) an attraction between the oppositely charged parts of adjacent molecules
c) strong bonds formed between adjacent atoms or ions
d) the nonpolar bond formed between two hydrogen atoms
e) the adhesive force formed between molecular hydrogen and oxygen
__ 164. What type of bonds hold the two large (macromolecular) strands together to form the
alpha-helix structure of DNA?
a) covalent
b) ionic
c) polar hydrogen
d) nonpolar covalent
e) hydrogen
__ 165. When two atoms are equally electronegative they will interact to form
a) equal numbers of isotopes.
b) ions.
c) nonpolar covalent bonds.
d) polar covalent bonds.
e) ionic bonds.
__ 166. If you place a paper towel in a dish of water, the water will move up the towel by capillary
action. What property of water gives rise to capillary action?
a) Water molecule separate into H+ and OH- ions.
b) Water is a good solvent.
c) Water molecules have hydrophobic interactions.
d) Water can form hydrogen bonds.
e) Water takes up large amounts of heat when it vaporizes.
__ 167. If you place the corner of a paper towel into a droplet of water the water moves across
the paper towel. Which of the following would explain the movement of the water?
a) surface tension
b) cohesion
c) adhesion
d) both cohesion and adhesion
__ 168. Sweating is a useful cooling device for humans because
a) water takes up a great deal of heat in changing from its liquid state to its gaseous state.
b) water takes up a great deal of heat in changing from its solid state to its liquid state.
c) water can exist in three states at temperatures common on Earth.
d) water is an outstanding solvent.
e) water ionizes readily
__ 169. In the water molecule
a) the oxygen molecule is more electronegative than the hydrogens
b) the oxygen atom has an overall negative charge with the hydrogen atoms having an overall positive charge
c) unequal sharing of electrons results in a polar molecule
d) All of the choices are correct.
__ 170. As a solid, water floats. This means that
a) solid water is less dense than liquid water
b) organisms in ponds, lakes, and reservoirs can survive under the ice cover
c) this is due to hydrogen bonding changes
d) All of the choices are correct.
__ 171. A coastal climate is moderated primarily by which of the following properties of water?
Water
a) is the universal solvent
b) is cohesive and adhesive
c) resists changes of state
d) has a high surface tension.
True – False
__ 172. Water moderates the temperatures on earth because it can absorb and release large
amounts of heat.
a) True
b) False
__ 173. Water molecules are held together by ionic bonds.
a) True
b) False
__ 174. Water surface tension is a result of the adhesive nature of water molecules.
a) True
b) False
__ 175. Most liquids become less dense upon solidification, but water is different in that it
becomes more dense when it solidifies.
a) True
b) False
Short Answer
__ 176. The water strider skates along the surface of water due to a property of liquids called
_________________.
__ 177. The attraction between a slight positive charge on a hydrogen atom and the slight
negative charge of a nearby atom is a __________________.
__ 178. Describe the key properties of water that make it so important in biological systems.
__ 179. What property of water is responsible for the ability of plants to get water from their roots
up to their leaves?
__ 180. Describe a hydrogen bond, and explain how it is related to a polar covalent bond.
__ 181. List and describe five properties of water that make it important in the presence of life on
earth.
__ 182. Discuss why the density of ice relative to that of liquid water makes life possible on earth.
Essay
Bonds – Water and Hydrophobicity
Multiple Choice
__ 183. The COHESIVE PROPERTIES of WATER help the molecules stay together as they are
pulled from plant roots up to the leaves. This cohesive property of water is due to:
a) hydrogen bonding between oxygen and hydrogen in the same water molecule;
b) hydrophobic interactions between water molecules;
c) hydrophilic interactions between water molecules;
d) hydrogen bonding between adjacent water molecules;
e) ionic bonds formed between water molecules.
__ 184. Which bonds must be broken for water to vaporize?
a) ionic bonds
b) nonpolar covalent bonds
c) polar covalent bonds
d) hydrogen bonds
e) both polar covalent bonds and hydrogen bonds are correct.
__ 185. IN ONE MOLECULE OF WATER, each hydrogen atom is held close to the oxygen atom with
single ___________ bonds.
a) hydrogen;
b) hydrophobic;
c) covalent;
d) ionic;
e) municipal.
__ 186. With which part of a membrane (phospho-) lipid molecule does water associate?
a) non-polar;
b) hydrophobic;
c) polar;
d) hydrocarbon;
e) fatty acid chain.
__ 187. Water is such an excellent solvent primarily because
a) it forms bonds with many charged and polar molecules
b) it contains hydrogen
c) it is relatively small
d) it is hydrophobic
e) none of the above
__ 188. Life on earth is dependent on all the properties of water as well as the abundance of
water. Which property of water is probably most important for the functioning of organisms
at the molecular level?
a) cohesion and high surface tension
b) high specific heat
c) high heat of vaporization
d) expansion upon freezing
e) versatility as a solvent
__ 189. Which of the following statements about water is correct?
a) Water is more dense as a solid than it is as a liquid.
b) Water is more dense at 100øC than it is at 37øC.
c) Water is a good solvent for lipids.
d) Compared to most other substances, the temperature of water rises sharply when it absorbs heat.
e) Compared to most liquids, the evaporation of water requires a large amount of heat.
__ 190. What do the following have in common with reference to water: cohesion, surface tension,
specific heat?
a) All are products of the structure of the hydrogen atom.
b) All are produced by covalent bonding.
c) All are properties related to hydrogen bonding.
d) All have to do with polarity of water molecules.
e) All are aspects of a semi-crystalline structure.
__ 191. The nutritional information on a cereal box shows that one serving of dry cereal has 90
calories (large C). If one were to burn a serving of cereal in a bomb calorimeter, the amount
of heat given off would be sufficient to raise the temperature of one kilogram of water how
many degrees Celsius?
a) 0.9 Celsius
b) 9.0 Celsius
c) 90.0 Celsius
d) 900.0 Celsius
e) 9000.0 Celsius
__ 192. The formation of ice during colder weather helps to temper the seasonal transition to
winter. This is mainly because:
a) the formation of hydrogen bonds releases heat.
b) the formation of hydrogen bonds absorbs heat.
c) there is less evaporative cooling of lakes.
d) ice melts each autumn afternoon.
e) ice is warmer than the winter air.
__ 193. What bonds must be broken for water to go from a liquid to a gas?
a) covalent
b) polar covalent
c) ionic
d) hydrogen
e) hydrophobic
__ 194. Ice is lighter and floats in water because it is a crystalline structure held together by
a) ionic bonds only.
b) hydrogen bonds only.
c) covalent bonds only.
d) both ionic and hydrogen bonds.
e) both ionic and covalent bonds.
__ 195. What does the energy to vaporize water do?
a) oxidize the water
b) reduce (add electrons to) the water molecules
c) decrease the number of hydrogen ions (H +) in water
d) break hydrogen bonds between water molecules
e) decrease the density of water
__ 196. What determines the cohesiveness of water molecules?
a) hydrophobic interactions
b) high specific heat
c) covalent bonds
d) hydrogen bonds
e) ionic bonds
__ 197. What do cohesion, surface tension, and adhesion have in common with reference to
water?
a) All are products of the structure of the hydrogen atom.
b) All are produced by covalent bonding.
c) All are properties related to hydrogen bonding.
d) All have to do with nonpolar covalent bonds.
e) All are aspects of a crystalline structure.
__ 198. Which of the following is a correct definition of a kilocalorie?
a) The amount of heat energy required to raise 1 gram of water by
b) one degree Fahrenheit.
c) The amount of heat energy required to raise one gram of water by
d) ten degrees Celsius.
e) The amount of heat energy required to raise one kilogram of water
f) by one degree Celsius.
g) A measure of the average kinetic energy of a pint of water.
h) The amount of energy in one kilogram of glucose.
__ 199. At what temperature is water at its densest?
a) 0C
b) 4C
c) 32C
d) 100C
e) 212C
__ 200. Temperature often increases when water condenses. Which behavior of
a) water is most directly responsible for this phenomenon?
b) change in density when it condenses to form a liquid or solid
c) reactions with other atmospheric compounds
d) release of heat by formation of hydrogen bonds
e) release of heat by breaking of hydrogen bonds
f) high surface tension
__ 201. A solute in water is most likely:
a) positively charged.
b) negatively charged.
c) neutral in charge.
d) hydrophobic.
e) polar.
__ 202. Which of the following substances is most likely to break into its individual components
when dissolved in water?
a) a substance whose atoms are joined by a nonpolar covalent bond.
b) a substance whose atoms are joined by a polar covalent bond.
c) a substance whose atoms are joined by an ionic bond.
d) a phosphate ion
__ 203. Hydrophobic molecules tend to be _________ by water.
a) attracted
b) absorbed
c) repelled
d) mixed
e) polarized
__ 204. Which statement is an accurate description of water molecules?
a) They are charged and polar.
b) They are charged and nonpolar.
c) They are uncharged and polar.
d) They are uncharged and nonpolar.
e) They are ionically bonded.
__ 205. Water will dissolve all of these except:
a) sugar
b) salt
c) CH3-CH2-OH
d) CH3-COOH
e) CH3-CH2-CH2-CH3
__ 206. Water is considered a good solvent because...
a) it can hydrogen bond with other polar molecules.
b) it dissolves ionically bonded molecules.
c) it dissolves all organic molecules.
d) a and b.
e) all of these.
__ 207. The fact that salt dissolves in water is best explained by:
a) The charged nature of water molecules
b) The polar nature of water molecules
c) The hydrophobic nature of salt
d) The ionic nature of water molecules
e) The hydrophobic nature of the water
__ 208. Hydrophilic molecules:
a) Form hydrogen bonds among themselves
b) Are neutral and nonpolar
c) Readily dissolve in water
d) a and c
e) a, b, and c
__ 209. What does H--O--H represent?
a) Atom of water
b) Mixture including water
c) Molecule of water
d) Planetary model of water
e) Ionic bonding of water
__ 210. Which term is based on the Greek root word for "water" and "fear"?
a) hydrostatic
b) homeostatic
c) hydrophobic
d) hydrophilic
e) hyperphobic
__ 211. A hydrocarbon is hydrophobic
a) at all times.
b) only in the living cell environment.
c) except when it has an attached ionized functional group.
d) in carbohydrates but not in lipids.
True – False
__ 212. Oil floats on the surface of water. This is because oil is hydrophylic.
a) True
b) False
__ 213. Molecules that are attracted to water are called hydrophobic.
a) True
b) False
__ 214. Ions dissolve easily in water because water is polar in nature.
a) True
b) False
Short Answer
__ 215. Explain the difference between hydrophilic and hydrophobic chemical interactions, and
explain how these interactions give fats and phospholipids their characteristics.
__ 216. Why is the oil layer separated from the vinegar layer in oil and vinegar salad dressing?
__ 217. Molecules that are electrically attracted to water molecules are __________________.
Essay
Bonds -- General
Multiple Choice
__ 218. Chemical bonds vary according to their strength. Which of the following correctly orders
the chemical bonds in order of their strength, starting with the one LEAST difficult to break?
I. Hydrogen bond
II. Ionic bond
III. Triple covalent bond
IV. Double covalent bond
V. Single covalent bond
a) I, II, III, IV, V
b) I, II, V, IV, III
c) II, I, III, IV, V
d) II, V, IV, III, I
e) III, IV, V, II, I
__ 219. The atomic number of neon is 10. Therefore, it
a) has 8 electrons in the outer electron shell.
b) forms ionic bonds.
c) forms hydrogen bonds.
d) Only A and B are correct.
e) A, B, and are correct.
__ 220. What determines the chemical properties of an atom?
a) the atomic mass of the atom.
b) the number of electrons in the outermost shell.
c) the number of neutrons in the nucleus.
d) the number of isotopes of the atom.
e) none of the above is correct.
__ 221. What are the chemical properties of atoms whose outer electron shells contain eight
electrons?
a) They form ionic bonds in aqueous solutions
b) They form covalent bonds in aqueous solutions
c) They are particularly stable and nonreactive
d) They tend to be solids
__ 222. The atomic number of neon is 10. Therefore, it
has 8 electrons in the outer electron shell.
is inert.
has an atomic mass of 10.
a) 1
b) 2
c) 3
d) Only 1 and 2 are correct.
e) 1, 2, and 3 are correct.
__ 223. What determines the chemical properties of an atom?
a) the number of protons in the nucleus
b) the number of electrons in the outermost energy level
c) the number of neutrons in the nucleus
d) the atomic mass of the atom
e) the number of isotopes of the atom
__ 224. What are the chemical properties of atoms whose outer electron shells contain eight
electrons?
a) They form ionic bonds in aqueous solutions.
b) They form covalent bonds in aqueous solutions.
c) They are particularly stable and nonreactive.
d) They tend to be solids.
e) Both C and D are correct.
__ 225. Which of the following bonds is the strongest (takes the most energy to break)?
a) ionic;
b) covalent;
c) polar;
d) hydrogen;
e) elemental.
__ 226. The combining properties of an atom depend on the number of:
a) shells in the atom.
b) orbitals found in the atom.
c) electrons in each orbital in the atom.
d) electrons in the outer shell in the atom.
e) hybridized orbitals in the atom.
__ 227. Atoms whose outer electron shells contain eight electrons tend to
a) form ionic bonds in aqueous solutions.
b) form covalent bonds in aqueous solutions.
c) be particularly stable and nonreactive.
d) be particularly unstable and very reactive.
e) be biologically important since they are present in organic molecules.
__ 228. The combining properties of an atom depend on the number of:
a) valence shells in the atom
b) orbitals found in the atom
c) electrons in each orbital in the atom
d) electrons in the outer valence shell in the atom
e) hybridized orbitals in the atom
__ 229. Atoms whose outer electron shells contain eight electrons tend to:
a) form ionic bonds in aqueous solutions
b) form covalent bonds in aqueous solutions
c) be particularly stable and non-reactive
d) be particularly unstable and very reactive
e) be biologically important since they are present in organic molecules
__ 230. If we put aside, for the moment, the concept of polarity in chemical bonds, then one
might correctly state that there are THREE BASIC TYPES of CHEMICAL BONDS that hold
compounds together. These are:
a) covalent bonds, hydrogen bonds, and municipal bond
b) ionic bonds, state bonds, and James Bond's
c) nuclear bonds, ionic bonds, and covalent bonds
d) proton bonds, electron bonds, and neutron bonds
e) hydrogen bonds, ionic bonds, and covalent bonds
__ 231. Why is a helium atom (Atomic #2) more stable than a hydrogen atom (Atomic #1)?
a) Two electrons completely fill its outermost electron shell.
b) Eight electrons completely fill its outermost electron shell.
c) The outermost electron shell is half-empty.
d) Helium atoms react readily with oxygen.
e) Hydrogen atoms react to form helium.
__ 232. Which of the following factors is the most significant when considering the reactivity of an
atom?
a) An atom is the smallest particle of an element.
b) A molecule is the smallest unit of a compound.
c) Atoms are held together by interactions between electrons.
d) The number of protons affects the size of the atom.
e) Atoms with many neutrons may be radioactive.
__ 233. For an atom to achieve maximum stability and become chemically unreactive, what must
occur?
a) Its outermost energy shell must be filled with electrons.
b) The number of electrons must equal the number of protons.
c) Sharing of electron pairs is necessary.
d) Ionization is required.
e) It must be inert.
a) nonpolar covalent bond
__ 234. Results from a transfer of electron(s) between atoms.
b) polar covalent bond
__ 235. Results from an unequal sharing of electrons between atoms.
__ 236. Best explains the attraction of water molecules to each other.
__ 237. Would be least affected by the presence of water.
c) ionic bond
d) hydrogen bond
e) electron-proton interaction
True – False
__ 238. In photosynthesis, energy from the sun is used to move electrons to higher energy levels;
then energy is released for food production as the electrons move back to their original
shells.
a) True
b) False
__ 239. Atoms can interact to give up, accept, or share electrons to produce a filled outer shell.
a) True
b) False
__ 240. Molecules form when energy relationships occur between atoms, called chemical bonds.
a) True
b) False
Short Answer
__ 241. A/An __________ bond involves shared electrons, whereas a/an __________ bond
involves the actual transfer of electrons.
__ 242. What is the difference between covalent and ionic bonds?
__ 243. Following nitrogen (78%) and oxygen (21%), argon is the next most common gas in the
atmosphere (less than 1%). Checking the table of elements, you discover that argon is one
of a family of atoms with outer shells already full of electrons. How is this related to the fact
that these atoms have virtually no biological importance?
Essay
Elements of Life
Multiple Choice
__ 244. Which type of molecule would be most abundant in a typical cell?
a) hydrocarbon
b) protein
c) water
d) lipid
e) carbohydrate
__ 245. Which of the following is NOT one of the four most common elements found in living
organisms?
a) hydrogen
b) oxygen
c) carbon
d) sulfur
e) nitrogen
__ 246. What do the four elements most abundant in life--carbon, oxygen, hydrogen and nitrogen-have in common?
a) They all have the same number of valence electrons.
b) Each element exists in only one isotopic form.
c) They are equal in electronegativity.
d) They are elements produced only by living cells.
e) They are all relatively light elements and can exist singly or in combination with other atoms as a gas.
__ 247. Which four elements make up approximately 96% of living matter?
a) carbon, hydrogen, nitrogen, oxygen
b) carbon, sulfur, phosphorus, hydrogen
c) carbon, sodium, chlorine, magnesium
d) carbon, oxygen, sulfur, calcium
e) oxygen, hydrogen, calcium, sodium
__ 248. All the following are true of hydrogen gas, H2, except (H atomic number = 1):
a) H2 is stable.
b) H2 is covalently bonded.
c) H2 shares one pair of electrons.
d) H2 is polar.
e) All of the above are true.
__ 249. Which of the following elements is NOT one of the six most common in living organisms?
a) carbon
b) oxygen
c) iron
d) nitrogen
e) hydrogen
True – False
__ 250. Why do you think small atoms are more commonly found in organic molecules rather than
large ones?
__ 251. Sulfur and phosphorus are among the six most common elements in living organisms.
a) True
b) False
__ 252. There are six elements that make up 100% of the body weight of an organism.
a) True
b) False
Short Answer
Essay
Organic
Multiple Choice
__ 253. The number of electrons carbon shares with oxygen molecules in a molecule of CO2.
a) 1
b) 2
c) 3
d) 4
e) 5
__ 254. Carbon is part of so many different substances because:
a) carbon generally forms two bonds with a variety of other atoms
b) carbon generally forms four bonds with a variety of atoms
c) carbon ionizes easily
d) carbon is a polar compound
e) none of the above
__ 255. An atom, such as carbon, that has FOUR ELECTRONS in its outer shell should form
COVALENT BONDS with ADJACENT ATOMS that can share electrons from its outer shell.
a) one
b) two
c) three
d) four
e) five
__ 256. Which of the following is an example of an organic compound?
a) plastic
b) cotton
c) base
d) acid
e) water
__ 257. Which of the following is the best description of organic compounds?
a) carbon atoms covalently bonded to other carbon atoms
b) polymers composed of many monomer subunits
c) compounds with covalent bonds that are unequally shared with other atoms
d) compounds all containing carbon, hydrogen, oxygen and nitrogen
e) carbon compounds all having a linear order of atoms
__ 258. The part of the atom of greatest biological interest is the
a) proton.
b) electron.
c) neutron.
d) innermost electron shell.
e) none of the above.
__ 259. Which property of the carbon atom gives it compatibility with a greater number of
different elements than any other type of atom?
1. Carbon has 6-8 neutrons.
2. Carbon has a valence of 4.
3. Carbon forms ionic bonds.
a) 1
b) 2
c) 3
d) Only 1 and 3 are correct.
e) 1, 2, and 3 are correct.
__ 260. Organic chemistry is a science based on the study of
a) functional groups.
b) vital forces interacting with matter.
c) carbon compounds.
d) water and its interaction with other kinds of molecules.
e) the properties of oxygen.
__ 261. How many electron pairs does carbon share in order to complete its valence shell?
a) 1
b) 2
c) 3
d) 4
e) 5
__ 262. What is the reason why hydrocarbons are not soluble in water?
a) They are hydrophilic.
b) The C-H bond is nonpolar.
c) They do not ionize.
d) They are large molecules.
e) They are lighter than water.
__ 263. A hydrocarbon and an alcohol molecule could be separated by chromatography in a
nonpolar solvent because
a) alcohol is soluble in the solvent and hydrocarbons are not soluble.
b) a nonpolar solvent would carry the hydrocarbon farther in the system.
c) a nonpolar solvent would carry the alcohol farther into the system.
d) they will separate on the basis of color.
e) the alcohol is a heavier molecule.
__ 264. Which of the following is the best description of organic compounds?
a) carbon atoms covalently bonded to other carbon atoms
b) polymers composed of many monomer subunits
c) compounds with covalent bonds that are unequally shared with other atoms
d) compounds all containing carbon, hydrogen, oxygen and nitrogen
e) carbon compounds all having a linear order of atoms
__ 265. Which property of the carbon atom gives it compatibility with a greater number of
different elements than any other type of atom?
a) Carbon has 6-8 neutrons.
b) carbon has a valence of 4.
c) Carbon forms ionic bonds.
d) Only A and C are correct.
e) A, B, and C are correct.
__ 266. The diversity of organic molecules is due to all of the following except the fact that
a) carbon needs four electrons to complete its outer shell.
b) carbon can form single and double bonds with itself and other elements.
c) organic molecules always contain covalent bonds.
d) carbon can bond with as many as four other elements.
__ 267. Organic molecules are those that contain at least
a) carbon.
b) carbon and oxygen.
c) carbon and hydrogen.
d) carbon, oxygen, and hydrogen.
e) carbon, sulfur, and hydrogen.
__ 268. The differences between organic and inorganic molecules do not follow simple absolute
rules. However, most organic molecules are associated with living organisms. Which of the
following statements does NOT correspond to the general distinctions between these types
of molecules?
a) Carbon dioxide (CO2) lacks hydrogen atoms found in organic molecules.
b) Formaldehyde (CH2O) is a small molecule compared to most organic molecules.
c) Salt (Na+Cl- ) is not an organic molecule but is important to the life of many organisms.
d) Because they are in living organisms, organic carbon atoms are different from the inorganic carbon atoms
forming the molecular structure of soot or a diamond.
True – False
__ 269. All molecules that contain carbon are considered organic molecules.
a) True
b) False
__ 270. Inorganic molecules are only found in nonliving matter.
a) True
b) False
__ 271. Carbon contains six electrons in its outer shell.
a) True
b) False
__ 272. Carbon can form covalent bonds with as many as four other atoms.
a) True
b) False
__ 273. Carbon compounds can form rings or long chains.
a) True
b) False
Short Answer
__ 274. What are two main common features of organic molecules?
__ 275. Carbon provides a versatile backbone for macromolecules. With an atomic number of 6,
carbon can form up to __________ different __________ bonds.
__ 276. _______________ molecules are synthesized by living organisms.
__ 277. List those characteristics of carbon that make it the most important element in organic
molecules.
Essay
Functional groups
Multiple Choice
__ 278. A compound contains hydroxyl groups as it’s predominate functional group. Which of the
following statements is true concerning this compound?
a) It is probably a lipid.
b) It should dissolve in water.
c) It should dissolve in a non-polar solvent.
d) It won't form hydrogen bonds with water.
e) It is hydrophobic.
__ 279. Which of the following contains nitrogen in addition to carbon, oxygen, and hydrogen?
a) an alcohol such as ethanol
b) a compound of fats such as glycerol
c) a steroid such as testosterone
d) an amino acid such as glycine
e) a hydrocarbon such as benzene
__ 280. Which is the best description of a carbonyl group?
a) a carbon and hydrogen atom
b) an oxygen double bonded to a carbon and a hydroxyl group
c) a nitrogen and a hydrogen bonded to a carbon atom
d) a sulfur and a hydrogen bonded to a carbon atom
e) a carbon atom joined to an oxygen atom by a double bond
__ 281. Forms covalent crosslinks within or between protein molecules.
a) -OH
b) -CÍO
c) -COOH
d) -NH2
e) -SH
__ 282. Which of the following is a false statement concerning amine groups?
a) They are basic.
b) They are found in amino acids.
c) They contain nitrogen.
d) They are nonpolar.
e) They are components of urea.
__ 283. Which two functional groups are always found in amino acids?
a) amine and sulfhydryl
b) carbonyl and carboxyl
c) carboxyl and amino
d) alcohol and aldehyde
e) ketone and amino
__ 284. Amino acids are acids because they possess which functional group?
a) amino
b) alcohol
c) carboxyl
d) sulfhydryl
e) aldehyde
__ 285. Which functional groups can act as acids?
a) amine and sulfhydryl
b) carbonyl and carboxyl
c) carboxyl and phosphate
d) alcohol and aldehyde
e) ketone and amine
__ 286. Which is a hydroxyl group?
a) -OH
b) -CO
c) -COOH
d) -NH2
e) -SH
__ 287. Which is an amino group?
a) -OH
b) -CO
c) -COOH
d) -NH2
e) -SH
__ 288. Which is a carboxyl group?
a) -OH
b) -CO
c) -COOH
d) -NH2
e) -SH
__ 289. What is the name of the functional group shown below?
a) carbonyl
b) methyl
O
c) dehydroxyl
R
C
d) carboxyl
O H
e) acetyl
__ 290. Which of the following is acidic, can dissociate and release H+.
a) -OH
b) -C=O
c) -COOH
d)
-NH2
e) -SH
__ 291. Amino acids are acids because they possess which functional group?
a) amino
b) alcohol
c) carboxyl
d) sulfhydryl
e) aldehyde
__ 292. Which is an alcohol?
a) R-OH
b) R-C=O
c) R-COOH
d)
R-NH2
e) R-SH
__ 293. Which is an amine?
a) R-OH
b) R-C=O
c) R-COOH
d)
R-NH2
e) R-SH
__ 294. Which is a carboxyl group?
a) -OH
b) -C=O
c) -COOH
d)
-NH2
e) -SH
__ 295. Match the following descriptions with the appropriate chemical group.
a) carboxyl group (acidic G. hydroxyl group (polar)
b) carboxyl group (basic) H. hydroxyl group (nonpolar)
c) amino group (acidic)
I. carbonyl group (polar)
d) amino group (basic)
J. carbonyl group (nonpolar)
e) phosphate group (acidic)
K. methyl group (polar)
f) phosphate group (basic) methyl group (nonpolar)
g) 1. R--NH2
2. R--CH4
3. R--CO--R
4. R--COOH
5. R--PO3H2
__ 296. A compound contains hydroxyl groups as its predominate functional group. Which of the
following statements is true concerning this compound?
a) It is probably a lipid.
b) It should dissolve in water.
c) It should dissolve in a non-polar solvent.
d) It is hydrophobic.
e) It won't form hydrogen bonds with water.
__ 297. Which of the following contains nitrogen in addition to carbon, oxygen, and hydrogen?
a) an alcohol such as ethanol
b) a compound of fats such as glycerol
c) a steroid such as testosterone
d) an amino acid such as glycine
e) a hydrocarbon such as benzene
__ 298. Which two functional groups are always found in amino acids?
a) amine and sulfhydryl
b) carbonyl and carboxyl
c) carboxyl and amine
d) alcohol and aldehyde
e) ketone and amine
__ 299. Which of the following biological substances contains both an amino group and a carboxyl
group?
a) alcohol
b) amino acid
c) saturated hydrocarbon
d) fatty acid
__ 300. The reactivity of an organic molecule is primarily dependent upon ____________of the
molecule.
a) the carbon skeleton
b) the attached functional groups such as an hydroxyl group
c) the isomer
d) All of the choices are correct.
True – False
Short Answer
__ 301. _________________ determine the characteristics and chemical reactivity of organic
molecules.
__ 302. Why are sugars soluble in water?
Essay
Isomers
Multiple Choice
__ 303. Which of the following is true of geometric isomers?
a) They have variations in arrangement around a double bond.
b) They have an asymmetric carbon that makes them mirror images.
c) They have the same chemical properties.
d) They have different molecular formulas.
e) Their atoms and bonds are arranged in different sequences.
__ 304. Glucose and fructose differ in
1. the number of carbon, hydrogen and oxygen atoms.
2. the types of carbon, hydrogen and oxygen atoms.
3. the arrangement of carbon, hydrogen and oxygen atoms.
a) 1
b) 2
c) 3
d) Only 1 and 2 are correct.
e) 1, 2, and 3 are correct.
__ 305. Both glyceraldehyde and dihydroxyacetone have the molecular formula C3H6O3. However,
the double-bonded oxygen in glyceraldehyde is attached to the end carbon while the
dihydroxyacetone molecule has the double-bonded oxygen bonded to the middle carbon.
a) These are isotopes and they will eventually decay to become the same stable molecule.
b) These are isomers and therefore have exactly the same chemical properties.
c) Both are hydrophobic hydrocarbons.
d) These molecules present different functional groups and are likely hydrophilic.
e) All of the choices are true.
__ 306. What term is used for molecules that have identical molecular formulas but the atoms in
each molecule are arranged differently?
a) isotope
b) isomer
c) homomolecules
d) organic
e) balanced
__ 307. Which is NOT an isomer of the other three?
a) glucose
b) ribose
c) fructose
d) galactose
True – False
Short Answer
Essay
pH
Multiple Choice
__ 308. Which of the following statements is true about buffer solutions? They
a) will always have a pH of 7.
b) tend to maintain a relatively constant pH.
c) maintain a constant pH when bases are added to them but not when
d) acids are added to them. d. cause a lowering of pH when acids are added to them.
e) are rarely found in living systems.
__ 309. A given solution is found to contain 0.0001 mole of hydrogen ion (H+). Which of the
following best describes this solution?
a) acidic: H+ acceptor
b) basic: H+ acceptor
c) acidic: H+ donor
d) basic: H+ donor
e) neutral
__ 310. It is correct to say that the action of buffers
a) is of relatively little significance in living systems.
b) tends to prevent great fluctuations in pH.
c) depends on the formation of a great number of hydrogen ions.
d) depends on the presence of many electron donors.
e) is to remove hydroxyl ions from organic acids.
__ 311. What does a pH of 7 indicate? 1. The solution is neutral. 2. The concentration of H+ ions
is 10-7 moles per liter. 3. There are no H+ ions in solution. 4. There are no OH- ions in
solution.
a) 1
b) 2
c) 3
d) 4
e) Both 1 and 2 are correct.
__ 312. Which of the following ionizes completely in solution and is therefore a strong acid?
a) NaOH
b) H2CO3
c) CH3COOH
d) NH2
e) HCl
__ 313. When carbon dioxide is added to pure water it forms a weak acid known as carbonic acid.
In a closed system, the carbonic acid reaches a chemical equilibrium with carbon dioxide and
water and with hydrogen ions and bicarbonate ions, thus: CO2 + H2O  H2CO3  H+ +
HCO3-Assume that the above reaction has reached equilibrium, and then NaOH (a strong
base) is added to the closed system. What would be the result of the NaOH addition?
a) Increased amount of CO2 and H2O.
b) Increased amount of H2CO3
c) Increased amount of H+ and H2CO3
d) Decreased amount of H+ and H2CO3
e) Decreased amount of H+ and increased amount of CO2.
__ 314. Which of the following solutions has the greater concentration of hydrogen ions (H+)?
a) gastric juice at pH 2
b) vinegar at pH 3
c) tomatoes at pH 4
d) black coffee at pH 5
e) seawater at pH 8
__ 315. Which of the following liquids does not have a measurable pH?
a) milk
b) sea water
c) gasoline
d) orange juice
e) distilled water
__ 316. A strong base would have a pH of about:
a) 1
b) 3
c) 5
d) 7
e) 13
__ 317. Blueberries grow best in moderately acidic soil. What is an appropriate pH of a soil that is
good for blueberries?
a) 1.2
b) 4.8
c) 7.0
d) 8.3
e) 12.0
__ 318. Which of the following solutions has the greater concentration of hydroxyl ions (OH-)?
a) gastric juice
b) vinegar
c) tomatoes
d) black coffee
e) seawater
__ 319. A solution with a pH of 3 has how many more H+ than a solution with a pH of 6?
a) 2 times more
b) 10 times more
c) 100 times more
d) 200 times more
e) 1000 times more
__ 320. What would be the pH of a solution with a hydroxyl ion concentration (OH-) of 10?
a) 2
b) 4
c) 8
d) 10
e) 14
__ 321. Buffers are substances which help resist shifts in pH by
a) releasing H + in acidic solutions.
b) releasing H + in basic solutions.
c) combining with H + in basic solutions.
d) combining with OH - in acidic solutions.
e) releasing OH - in basic solutions.
__ 322. Assume that acid rain has lowered the pH of a particular lake to pH 5.0. What is the
hydroxide ion concentration of this lake? 1. 1 X 10-5 moles of hydroxide ion per liter of lake
water; 2. 1 X 10-9 moles of hydroxide ion per liter of lake water; 3. 5.0 molar with regard to
hydroxide ion concentration; 4. 9.0 molar with regard to hydroxide ion concentration
a) 1
b) 2
c) 3
d) 4
e) Both 2 and 4 are correct.
__ 323. If the pH of a solution is decreased from 7 to 6, it means that the
a) concentration of H+ has decreased to 1/10 of what it was at pH 7.
b) concentration of H+ has increased 10 times what it was at pH 7.
c) concentration of OH- has increased 10 times what it was at pH 7.
d) concentration of OH- has increased by 1/7 of what it was.
e) solution has become more basic.
__ 324. What happens when water ionizes?
a) Equal amounts of hydrogen and hydroxyl ions are formed.
b) Ions are irreversibly formed.
c) Many ions are produced.
d) Anything in solution in water becomes ionized.
e) The water changes its pH because of the ions.
f) Which statement is NOT true about the pH scale?
__ 325. Which of the following would be a proposed mechanism by which stomach antacids work?
a) Antacids dilute the solution, therefore lowering the pH.
b) Antacids are bases and by definition can absorb H+ out of a solution.
c) Antacids are bases and by definition can absorb OH- out of a solution.
d) Antacids contain mostly water and so they neutralize the solution.
__ 326. If the acidic level of human blood increases, how is homeostasis maintained?
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+ and forms carbonic acid.
d) Answers a, b, and c all are correct.
__ 327. The scale indicates the relative concentrations of hydrogen and hydroxyl ions in a solution.
a) The scale ranges from 1 to 15.
b) pH 7 has a balanced level of H+ and OH-.
c) Anything below pH 7 is acidic and above pH 7 is basic.
d) A change of one pH unit represents a ten-fold increase or decrease in hydroxyl ion concentration.
__ 328. An abandoned Indiana coal mine spoil bank contains chunks of pyrite minerals. Under
constant erosion and weathering, the pyrites leech large amounts of sulfuric acid (H2SO4).
The spoil banks are also mixed with large quantities of basic limestone and clay carbonates.
What should occur over time?
a) The pH level will drop until all acid has washed out.
b) The pH level will remain at 7.0 because of constant washing with rain.
c) The pH level will remain at 7.0 because all acid will be immediately neutralized by bases.
d) The pH levels will be spotty and vary over time, first more acidic but drifting back toward 7.0.
e) Bases always dominate over acids.
__ 329. If the pH of cytoplasm is approximately 7.2, the cytoplasm is
a) very acidic.
b) slightly acidic.
c) precisely neutral.
d) slightly alkaline.
e) very alkaline.
__ 330. The blood buffer reaction described by H2CO3  H + HCO3 - indicates that
a) scientists are uncertain which direction the equation flows.
b) the reaction can flow either direction depending on whether there is an excess of hydrogen or hydroxide
ions.
c) any reaction in one direction causes an immediate reverse reaction.
d) chemicals can swing wildly from acid to basic.
e) there is really no difference in chemistry whether a molecule is formed or dissociated.
__ 331. What happens when hydrochloric acid (HCl) is added to 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.
__ 332. If a substance measures 7 on the pH scale, that substance:
a) Has equal concentration of H+ and OH- ions
b) May be lemon juice
c) Has greater concentration of OH- than H+ ions
d) Probably lacks OH- ions
e) Is basic
__ 333. A neutral solution...
a) has no H+
b) has no OHc) has equal amounts of H+ and OHd) is hydrophobic
e) has a pH of 0
__ 334. How do buffers work?
a) Soak up extra acid and base
b) Accept or release H+
c) Accept or release OHd) Convert H+ and OH- to water
e) Monitor the blood pH
__ 335. Human blood has a pH of about 7.4. This is
a) neutral
b) very acidic
c) slightly acidic
d) slightly basic
__ 336. All of the following reflect harm due to acid deposition from rain EXCEPT
a) leaching of aluminum from the soil into lakes which results in the formation of toxic methyl mercury
from mercury in the lake sediments
b) weakens trees in the forests and kills seedlings
c) increased agricultural yields
d) damage to marble and limestone monuments
__ 337. A weak acid or base that combines reversibly with hydrogen ions.
a) calorie
b) temperature
c) heat of vaporization
d) buffer
e) mole
__ 338. Prior to prescription medications to control stomach acid and "heart burn" people
consumed baking soda (sodium bicarbonate) to decrease their discomfort. This would
indicate that sodium bicarbonate
a) is an effective buffer
b) should be sold as a prescription drug
c) blocks acid production
d) None of the choices are correct.
True – False
__ 339. If a chemical accepted H+ from a solution, it could be considered both a base and a
buffer.
a) True
b) False
__ 340. Buffers are chemicals that can both take up and release hydrogen ions, thus maintaining
pH changes in a chemical system.
a) True
b) False
__ 341. Acids have pH values below 7, while bases have pH values above 7.
a) True
b) False
__ 342. A buffer is essential in living systems to maintain a constant pH.
a) True
b) False
Short Answer
__ 343. How does a base differ from an acid?
__ 344. Describe the pH scale and how it is used to indicate whether a substance is an acid, a
base, or neutral.
__ 345. Describe the action of a buffer and how it can be important in maintaining the pH of a
living system.