Question 1

Which statement explains why ice floats in liquid water?

Accepted Answer

A)  As water molecules go from the liquid to the solid state, their rate of motion decreases. 
B)  Water molecules maintain the same bent shape in liquid and solid states. 
C)  The ordered lattice structure of water molecules in ice is maintained by hydrogen bonds. 
D)  The arrangement of water molecules in ice results in fewer molecules per unit volume than in liquid water. 
E)  Water molecules maintain the same mass as they transition from the liquid to the solid state. 
A)  As water molecules go from the liquid to the solid state, their rate of motion decreases. 
B)  Water molecules maintain the same bent shape in liquid and solid states. 
C)  The ordered lattice structure of water molecules in ice is maintained by hydrogen bonds. 
D)  The arrangement of water molecules in ice results in fewer molecules per unit volume than in liquid water. 
E)  Water molecules maintain the same mass as they transition from the liquid to the solid state.

Question 2

Refer to the figure below.   The figure represents a helium atom.What change to this figure would allow it to represent an isotope of hydrogen?

Accepted Answer

A)  Remove one small circle from the outer ring, and remove two unlabeled circles from the center. 
B)  Remove one small circle from the outer ring, and remove one circle labeled with "+" and two unlabeled circles from the center. 
C)  Remove one small circle from the outer ring, and change one circle labeled with "+" to an unlabeled circle in the center. 
D)  Remove one small circle from the outer ring, and change one unlabeled circle to a circle labeled with "+" in the center. 
E)  Remove one small circle from the outer ring, and add one unlabeled circle to the center. 
A)  Remove one small circle from the outer ring, and remove two unlabeled circles from the center. 
B)  Remove one small circle from the outer ring, and remove one circle labeled with "+" and two unlabeled circles from the center. 
C)  Remove one small circle from the outer ring, and change one circle labeled with "+" to an unlabeled circle in the center. 
D)  Remove one small circle from the outer ring, and change one unlabeled circle to a circle labeled with "+" in the center. 
E)  Remove one small circle from the outer ring, and add one unlabeled circle to the center.

Question 3

Refer to the figure below.   The figure shows four examples of molecular interactions in biological samples.Can any of these be used as examples of hydrophilic or hydrophobic interactions?

Accepted Answer

A)  1, 2, and 3 hydrophilic; 4 hydrophobic 
B)  2 and 3 hydrophilic; 4 hydrophobic 
C)  2 hydrophilic; 4 hydrophobic 
D)  3 hydrophilic; 1 and 4 hydrophobic 
E)  2 and 3 hydrophilic; 1 and 4 hydrophobic 
A)  1, 2, and 3 hydrophilic; 4 hydrophobic 
B)  2 and 3 hydrophilic; 4 hydrophobic 
C)  2 hydrophilic; 4 hydrophobic 
D)  3 hydrophilic; 1 and 4 hydrophobic 
E)  2 and 3 hydrophilic; 1 and 4 hydrophobic

Question 4

Sweating is a useful cooling device for humans because water

Accepted Answer

A)  absorbs a great deal of heat in changing from its liquid state to its gaseous state. 
B)  absorbs a great deal of heat in changing from its solid state to its liquid state. 
C)  can exist in three states at temperatures common on Earth. 
D)  is an outstanding solvent. 
E)  ionizes readily. 
A)  absorbs a great deal of heat in changing from its liquid state to its gaseous state. 
B)  absorbs a great deal of heat in changing from its solid state to its liquid state. 
C)  can exist in three states at temperatures common on Earth. 
D)  is an outstanding solvent. 
E)  ionizes readily.

Question 5

Carbon and silicon have the same number of

Accepted Answer

A)  protons. 
B)  valence (outer shell) electrons. 
C)  neutrons. 
D)  electrons. 
E)  protons and neutrons. 
A)  protons. 
B)  valence (outer shell) electrons. 
C)  neutrons. 
D)  electrons. 
E)  protons and neutrons.

Question 6

A single carbon atom can bond a total of _______ hydrogen atoms, and the outer shell of each hydrogen atom then contains _______ electrons.

Accepted Answer

A)  two; two 
B)  two; four 
C)  four; four 
D)  four; two 
E)  eight; two 
A)  two; two 
B)  two; four 
C)  four; four 
D)  four; two 
E)  eight; two

Question 7

Refer to the figure below showing part of the periodic table.   What is the name of the element that has the same number of valence electrons as silicon (Si)?

Accepted Answer

The answer of Refer to the figure below showing part...

Question 8

Which symbol represents an atom with atomic number 28?

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 9

Which characteristic of water contributes most to the relatively constant temperatures of the oceans?

Accepted Answer

A)  Water has the ability to ionize slightly. 
B)  Water has a high specific heat. 
C)  Salt water has low surface tension. 
D)  Salt water is denser than freshwater. 
E)  Water requires a small amount of heat energy to raise its temperature. 
A)  Water has the ability to ionize slightly. 
B)  Water has a high specific heat. 
C)  Salt water has low surface tension. 
D)  Salt water is denser than freshwater. 
E)  Water requires a small amount of heat energy to raise its temperature.

Question 10

Refer to the figure below.   Which illustration represents the attractive forces responsible for the shape of the water surface in the glassware shown?

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 11

Which statement about isotopes is false?

Accepted Answer

A)  Isotopes vary in the number of neutrons but not the number of protons. 
B)  Radioisotopes are unstable and spontaneously emit radiation. 
C)  Isotopes have the same atomic number but not the same atomic weight. 
D)  Isotopes have virtually the same chemical reactivity. 
E)  Deuterium is an isotope of hydrogen containing one proton and two neutrons. 
A)  Isotopes vary in the number of neutrons but not the number of protons. 
B)  Radioisotopes are unstable and spontaneously emit radiation. 
C)  Isotopes have the same atomic number but not the same atomic weight. 
D)  Isotopes have virtually the same chemical reactivity. 
E)  Deuterium is an isotope of hydrogen containing one proton and two neutrons.

Question 12

A biologist is conducting experiments on human muscle and collects a variety of data, listed below.Which type of data would provide evidence for the claim that living organisms are chemically dynamic?

Accepted Answer

A)  Amount of force generated by a muscle fiber 
B)  Length of a muscle fiber 
C)  Elemental composition of a muscle fiber 
D)  Rate of metabolism of glucose by a muscle fiber 
E)  Duration of contraction of a muscle fiber 
A)  Amount of force generated by a muscle fiber 
B)  Length of a muscle fiber 
C)  Elemental composition of a muscle fiber 
D)  Rate of metabolism of glucose by a muscle fiber 
E)  Duration of contraction of a muscle fiber

Question 13

Which element has a higher atomic mass than phosphorus?

Accepted Answer

A)  Hydrogen 
B)  Oxygen 
C)  Sodium 
D)  Magnesium 
E)  Calcium 
A)  Hydrogen 
B)  Oxygen 
C)  Sodium 
D)  Magnesium 
E)  Calcium

Question 14

Given that Avogadro's number is 6.02 × 1023, how many molecules of KCl are there in 10-13 liter of a 1 M KCl solution?

Accepted Answer

A)  6.02 × 1036 
B)  6.02 × 1010 
C)  6.02 × 10-10 
D)  6.02 × 103 
E)  6.02 × 1013 
A)  6.02 × 1036 
B)  6.02 × 1010 
C)  6.02 × 10-10 
D)  6.02 × 103 
E)  6.02 × 1013

Question 15

Which correctly ranks the relative strengths of bonds and interactions?

Accepted Answer

A) Covalent bond > ionic attraction > hydrogen bond > hydrophobic interaction > van der Waals. B) Covalent bond > ionic attraction = hydrogen bond > hydrophobic interaction > van der Waals. C) Covalent bond < ionic attraction < hydrogen bond < hydrophobic interaction < van der Waals. D) Covalent bond < ionic attraction = hydrogen bond < hydrophobic interaction < van der Waals. E) Covalent bond < ionic attraction = van der Waals < hydrophobic interaction < hydrogen bond. A) Covalent bond > ionic attraction > hydrogen bond > hydrophobic interaction > van der Waals. B) Covalent bond > ionic attraction = hydrogen bond > hydrophobic interaction > van der Waals. C) Covalent bond < ionic attraction < hydrogen bond < hydrophobic interaction < van der Waals. D) Covalent bond < ionic attraction = hydrogen bond < hydrophobic interaction < van der Waals. E) Covalent bond < ionic attraction = van der Waals < hydrophobic interaction < hydrogen bond.

Question 16

The mass number of an atom is determined primarily by the _______ it contains.

Accepted Answer

A)  number of electrons 
B)  number of protons 
C)  sum of the number of protons and the number of electrons 
D)  sum of the number of protons and the number of neutrons 
E)  number of charges 
A)  number of electrons 
B)  number of protons 
C)  sum of the number of protons and the number of electrons 
D)  sum of the number of protons and the number of neutrons 
E)  number of charges

Question 17

The covalent bonds in methane, CH4, are very strong and require a great deal of energy to break.This is because in forming each bond, electrons are shared between carbon atoms and hydrogen atoms such that the _______ of each atom become filled, which is a highly stable condition.

Accepted Answer

Question 18

Refer to the figures below.   Rank the compounds in order of lowest to highest heat capacity per mole of compound.

Accepted Answer

A)  C < A < B 
B)  A < C < B 
C)  B < A < C 
D)  B < C < A 
E)  C < B < A 
A)  C < A < B 
B)  A < C < B 
C)  B < A < C 
D)  B < C < A 
E)  C < B < A

Question 19

According to the periodic table, the compound that sulfur forms with hydrogen is most like

Accepted Answer

A)  NH4+. 
B)  NH3. 
C)  H2O. 
D)  HF. 
E)  HCl. 
A)  NH4+. 
B)  NH3. 
C)  H2O. 
D)  HF. 
E)  HCl.

Question 20

Although air temperatures at a site on the coast of California can swing widely in very short periods of time, marine animals in the ocean at this site do not experience the same wide temperature swings.Which statement explains this observation?

Accepted Answer

A)  Hydrogen bonding between water molecules results in the formation of a rigid lattice-like structure in the solid state. 
B)  The density of water changes with temperature as the average distance between water molecules changes. 
C)  A great deal of energy absorbed by water goes into breaking hydrogen bonds between water molecules. 
D)  Water molecules at the surface are hydrogen-bonded to other water molecules below them. 
E)  The polar nature of water molecules makes it an excellent solvent for dissolving polar substances. 
A)  Hydrogen bonding between water molecules results in the formation of a rigid lattice-like structure in the solid state. 
B)  The density of water changes with temperature as the average distance between water molecules changes. 
C)  A great deal of energy absorbed by water goes into breaking hydrogen bonds between water molecules. 
D)  Water molecules at the surface are hydrogen-bonded to other water molecules below them. 
E)  The polar nature of water molecules makes it an excellent solvent for dissolving polar substances.

Exam 2: Small Molecules and the Chemistry of Life

Which statement explains why ice floats in liquid water?

Refer to the figure below. The figure represents a helium atom.What change to this figure would allow it to represent an isotope of hydrogen?

Refer to the figure below. The figure shows four examples of molecular interactions in biological samples.Can any of these be used as examples of hydrophilic or hydrophobic interactions?

Sweating is a useful cooling device for humans because water

Carbon and silicon have the same number of

A single carbon atom can bond a total of _______ hydrogen atoms, and the outer shell of each hydrogen atom then contains _______ electrons.

Refer to the figure below showing part of the periodic table. What is the name of the element that has the same number of valence electrons as silicon (Si)?

Which symbol represents an atom with atomic number 28?

Which characteristic of water contributes most to the relatively constant temperatures of the oceans?

Refer to the figure below. Which illustration represents the attractive forces responsible for the shape of the water surface in the glassware shown?

Which statement about isotopes is false?

A biologist is conducting experiments on human muscle and collects a variety of data, listed below.Which type of data would provide evidence for the claim that living organisms are chemically dynamic?

Which element has a higher atomic mass than phosphorus?

Given that Avogadro's number is 6.02 × 1023, how many molecules of KCl are there in 10-13 liter of a 1 M KCl solution?

Which correctly ranks the relative strengths of bonds and interactions?

The mass number of an atom is determined primarily by the _______ it contains.

The covalent bonds in methane, CH4, are very strong and require a great deal of energy to break.This is because in forming each bond, electrons are shared between carbon atoms and hydrogen atoms such that the _______ of each atom become filled, which is a highly stable condition.

Refer to the figures below. Rank the compounds in order of lowest to highest heat capacity per mole of compound.

According to the periodic table, the compound that sulfur forms with hydrogen is most like

Although air temperatures at a site on the coast of California can swing widely in very short periods of time, marine animals in the ocean at this site do not experience the same wide temperature swings.Which statement explains this observation?

Studying Life

Proteins, Carbohydrates, and Lipids

Nucleic Acids and the Origin of Life

Cells: the Working Units of Life

Cell Membranes

Cell Communication and Multicellularity

Energy, Enzymes, and Metabolism

Pathways That Harvest Chemical Energy

Photosynthesis: Energy From Sunlight

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

Dna and Its Role in Heredity

From Dna to Protein: Gene Expression

Gene Mutation and Molecular Medicine

Regulation of Gene Expression

Genomes

Recombinant Dna and Biotechnology

Mechanisms of Evolution

Reconstructing and Using Phylogenies

Speciation

Evolution of Genes and Genomes

The History of Life on Earth

Bacteria, Archaea, and Viruses

The Origin and Diversification of Eukaryotes

Plants Without Seeds: From Water to Land

The Evolution of Seed Plants

The Evolution and Diversity of Fungi

Animal Origins and the Evolution of Body Plans

Protostome Animals

Deuterostome Animals

The Plant Body

Transport in Plants

Plant Nutrition

Regulation of Plant Growth

Reproduction in Flowering Plants

Plant Responses to Environmental Challenges

Physiology, Homeostasis, and Temperature Regulation

Animal Hormones

Immunology: Animal Defense Systems

Animal Reproduction

Animal Development

Neurons, Glia, and Nervous Systems

Sensory Systems

The Mammalian Nervous System: Structure and Higher Functions

Musculoskeletal Systems

Gas Exchange

Circulatory Systems

Nutrition, Digestion, and Absorption

Salt and Water Balance and Nitrogen Excretion

Animal Behavior

The Physical Environment and Biogeography of Life

Populations

Species Interactions

Communities

Ecosystems

A Changing Biosphere

Filters

A single carbon atom can bond a total of _ hydrogen atoms, and the outer shell of each hydrogen atom then contains _ electrons.

Given that Avogadro's number is 6.02 × 10²³, how many molecules of KCl are there in 10^-13 liter of a 1 M KCl solution?

The covalent bonds in methane, CH₄, are very strong and require a great deal of energy to break.This is because in forming each bond, electrons are shared between carbon atoms and hydrogen atoms such that the _______ of each atom become filled, which is a highly stable condition.