Question 1

Refer to the Bohr model of methane shown below.   Which statement about this structure is true?

Accepted Answer

A)  All bonds are ionic bonds. 
B)  All bonds are hydrogen bonds. 
C)  All bonds contain paired electrons from carbon. 
D)  All bonds contain paired electrons from hydrogen. 
E)  All bonds contain paired electrons shared between carbon and hydrogen. 
A)  All bonds are ionic bonds. 
B)  All bonds are hydrogen bonds. 
C)  All bonds contain paired electrons from carbon. 
D)  All bonds contain paired electrons from hydrogen. 
E)  All bonds contain paired electrons shared between carbon and hydrogen.

Question 2

Which shows the elements carbon (C), hydrogen (H), oxygen (O), nitrogen (N), and phosphorus (P) in decreasing order by the number of covalent bonds they usually form?

Accepted Answer

A)  C > P > N > O > H 
B)  P > O > C > N > H 
C)  P > C > N > O > H 
D)  P > C > O > N > H 
E)  P > C > O > H > N 
A)  C > P > N > O > H 
B)  P > O > C > N > H 
C)  P > C > N > O > H 
D)  P > C > O > N > H 
E)  P > C > O > H > N

Question 3

Polar molecules

Accepted Answer

A)  have electric charges that are unequally distributed. 
B)  have the ability to form ions when dissolved in water. 
C)  have electric charges that are equally distributed. 
D)  have bonds with an overall negative charge. 
E)  have bonds with an overall positive charge. 
A)  have electric charges that are unequally distributed. 
B)  have the ability to form ions when dissolved in water. 
C)  have electric charges that are equally distributed. 
D)  have bonds with an overall negative charge. 
E)  have bonds with an overall positive charge.

Question 4

How does the ionic compound magnesium chloride form?

Accepted Answer

A)  A magnesium atom loses one electron, a chlorine atom gains one electron, and an ionic bond forms between the chloride ion and the magnesium ion. 
B)  A magnesium atom loses two electrons, two chlorine atoms each gain one electron, and an ionic bond forms between each chloride ion and the magnesium ion. 
C)  Two magnesium atoms each lose one electron, two chlorine atoms each gain one electron, and an ionic bond forms between each chloride ion and each magnesium ion. 
D)  A chlorine atom loses one electron, a magnesium atom gains one electron, and an ionic bond forms between the chloride ion and the magnesium ion. 
E)  Two chlorine atoms each lose one electron, a magnesium atom gains two electrons, and an ionic bond forms between each chloride ion and the magnesium ion. 
A)  A magnesium atom loses one electron, a chlorine atom gains one electron, and an ionic bond forms between the chloride ion and the magnesium ion. 
B)  A magnesium atom loses two electrons, two chlorine atoms each gain one electron, and an ionic bond forms between each chloride ion and the magnesium ion. 
C)  Two magnesium atoms each lose one electron, two chlorine atoms each gain one electron, and an ionic bond forms between each chloride ion and each magnesium ion. 
D)  A chlorine atom loses one electron, a magnesium atom gains one electron, and an ionic bond forms between the chloride ion and the magnesium ion. 
E)  Two chlorine atoms each lose one electron, a magnesium atom gains two electrons, and an ionic bond forms between each chloride ion and the magnesium ion.

Question 5

Ice floats because the ice crystals

Accepted Answer

A)  contain fewer water molecules per volume than the liquid water. 
B)  are more dense than liquid water. 
C)  form heat, which makes water expand. 
D)  can move quickly and therefore can float. 
E)  have a high surface tension. 
A)  contain fewer water molecules per volume than the liquid water. 
B)  are more dense than liquid water. 
C)  form heat, which makes water expand. 
D)  can move quickly and therefore can float. 
E)  have a high surface tension.

Question 6

All of the elements listed below follow the octet rule except

Accepted Answer

A)  hydrogen. 
B)  chlorine. 
C)  carbon. 
D)  sodium. 
E)  nitrogen. 
A)  hydrogen. 
B)  chlorine. 
C)  carbon. 
D)  sodium. 
E)  nitrogen.

Question 7

Refer to the figure below.   Which statement about the figure is true?

Accepted Answer

A)  It shows a chemical change because the products differ from the reactants. 
B)  It shows a chemical change because the three molecules were transformed into two molecules. 
C)  It shows a chemical change because energy was released as a result of the change. 
D)  It does not accurately show a chemical change because the numbers of atoms on the two sides of the arrow differ. 
E)  It does not accurately show a chemical change because energy is shown on the wrong side of the arrow. 
A)  It shows a chemical change because the products differ from the reactants. 
B)  It shows a chemical change because the three molecules were transformed into two molecules. 
C)  It shows a chemical change because energy was released as a result of the change. 
D)  It does not accurately show a chemical change because the numbers of atoms on the two sides of the arrow differ. 
E)  It does not accurately show a chemical change because energy is shown on the wrong side of the arrow.

Question 8

Refer to the figure below showing various chemical bonds and interactions.   Nonpolar molecules would likely exhibit which type(s) of bonds or interactions?

Accepted Answer

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

Question 9

A car sitting in the sun on a hot summer day becomes very hot to the touch.Water in a bucket sitting next to the car under the same conditions for the same length of time feels cool to the touch.Which statement explains this difference?

Accepted Answer

A)  Radiant energy goes into breaking the forces of attraction between water molecules before increasing their rate of motion. 
B)  Radiant energy is reflected off the surface of water rather than being absorbed by the water molecules. 
C)  Radiant energy cannot easily penetrate water because of its density and is therefore not absorbed readily. 
D)  Radiant energy is absorbed poorly by liquids, compared with solids. 
E)  Radiant energy is absorbed by certain elements more readily than by other elements. 
A)  Radiant energy goes into breaking the forces of attraction between water molecules before increasing their rate of motion. 
B)  Radiant energy is reflected off the surface of water rather than being absorbed by the water molecules. 
C)  Radiant energy cannot easily penetrate water because of its density and is therefore not absorbed readily. 
D)  Radiant energy is absorbed poorly by liquids, compared with solids. 
E)  Radiant energy is absorbed by certain elements more readily than by other elements.

Question 10

The ball-and-stick structure of methane (CH4) shows that

Accepted Answer

A)  the molecule is flat. 
B)  the molecule is not polar. 
C)  all bonds are hydrogen bonds. 
D)  all bond angles are different. 
E)  all bond lengths are different. 
A)  the molecule is flat. 
B)  the molecule is not polar. 
C)  all bonds are hydrogen bonds. 
D)  all bond angles are different. 
E)  all bond lengths are different.

Question 11

Which statement is true?

Accepted Answer

A)  Carbon makes the same number of covalent bonds as phosphorus does. 
B)  Oxygen makes more covalent bonds than sulfur does. 
C)  Sulfur makes more covalent bonds than carbon does. 
D)  Hydrogen makes more covalent bonds than carbon does. 
E)  Oxygen makes fewer covalent bonds than nitrogen does. 
A)  Carbon makes the same number of covalent bonds as phosphorus does. 
B)  Oxygen makes more covalent bonds than sulfur does. 
C)  Sulfur makes more covalent bonds than carbon does. 
D)  Hydrogen makes more covalent bonds than carbon does. 
E)  Oxygen makes fewer covalent bonds than nitrogen does.

Question 12

How do the densities of ice and liquid water differ? Justify your answer with a sketch.

Accepted Answer

Ice is less dense than liquid water. Thi

Question 13

Which statement could be used to explain why an atom is electrically neutral?

Accepted Answer

A)  The atom has a nucleus consisting of protons and neutrons. 
B)  Electrons move in the space surrounding the atomic nucleus. 
C)  The atom contains an equal number of protons and electrons. 
D)  Two atoms of the same element can have differing numbers of neutrons. 
E)  All atoms contain positively charged protons and negatively charged electrons. 
A)  The atom has a nucleus consisting of protons and neutrons. 
B)  Electrons move in the space surrounding the atomic nucleus. 
C)  The atom contains an equal number of protons and electrons. 
D)  Two atoms of the same element can have differing numbers of neutrons. 
E)  All atoms contain positively charged protons and negatively charged electrons.

Question 14

Which correctly shows the relative strengths of chemical bonds in decreasing order?

Accepted Answer

A)  Covalent, ionic, hydrogen, van der Waals forces 
B)  Ionic, covalent, hydrogen, van der Waals forces 
C)  van der Waals forces, covalent, ionic, hydrogen 
D)  Hydrogen, covalent, van der Waals forces, ionic 
E)  Ionic, covalent, van der Waals forces, hydrogen 
A)  Covalent, ionic, hydrogen, van der Waals forces 
B)  Ionic, covalent, hydrogen, van der Waals forces 
C)  van der Waals forces, covalent, ionic, hydrogen 
D)  Hydrogen, covalent, van der Waals forces, ionic 
E)  Ionic, covalent, van der Waals forces, hydrogen

Question 15

The electric charge in _______ covalent bonds is unequally distributed because one nucleus has a stronger attraction for the electrons than the other has.

Accepted Answer

The answer of The electric charge in _______ covalent bonds...

Question 16

Refer to the figure below.   Which diagram represents magnesium (Mg; atomic number 12)?

Accepted Answer

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

Question 17

A(n) _______ atom has 7 neutrons and a mass number of 15.

Accepted Answer

The answer of A(n) _______ atom has 7 neutrons and...

Question 18

Refer to the two balanced chemical equations below.
(1) CH4 + 2 O2 F1F1F1S1F1F1F10F1F1F1S1F1F1F10 CO2 + 2 H2O + 890 kJ
(2) C3H8 + 5 O2 F1F1F1S1F1F1F10 3 CO2 + 4 H2O + 2,220 kJ
According to the information given, reaction 2 involves a _______ change in energy than reaction 1.

Accepted Answer

Question 19

Hydrogen bonds

Accepted Answer

A)  form between two hydrogen atoms. 
B)  form only between hydrogen and oxygen atoms within a molecule. 
C)  form only between a weak electronegative atom and hydrogen. 
D)  involve a transfer of electrons. 
E)  form weak interactions but can provide structural stability when many are found in a single molecule. 
A)  form between two hydrogen atoms. 
B)  form only between hydrogen and oxygen atoms within a molecule. 
C)  form only between a weak electronegative atom and hydrogen. 
D)  involve a transfer of electrons. 
E)  form weak interactions but can provide structural stability when many are found in a single molecule.

Question 20

The number of different natural elements found in the universe is closest to

Accepted Answer

A)  18. 
B)  54. 
C)  86. 
D)  94. 
E)  146. 
A)  18. 
B)  54. 
C)  86. 
D)  94. 
E)  146.

Exam 2: Small Molecules and the Chemistry of Life

Refer to the Bohr model of methane shown below. Which statement about this structure is true?

Which shows the elements carbon (C), hydrogen (H), oxygen (O), nitrogen (N), and phosphorus (P) in decreasing order by the number of covalent bonds they usually form?

Polar molecules

How does the ionic compound magnesium chloride form?

Ice floats because the ice crystals

All of the elements listed below follow the octet rule except

Refer to the figure below. Which statement about the figure is true?

Refer to the figure below showing various chemical bonds and interactions. Nonpolar molecules would likely exhibit which type(s) of bonds or interactions?

A car sitting in the sun on a hot summer day becomes very hot to the touch.Water in a bucket sitting next to the car under the same conditions for the same length of time feels cool to the touch.Which statement explains this difference?

The ball-and-stick structure of methane (CH4) shows that

Which statement is true?

How do the densities of ice and liquid water differ? Justify your answer with a sketch.

Which statement could be used to explain why an atom is electrically neutral?

Which correctly shows the relative strengths of chemical bonds in decreasing order?

The electric charge in _______ covalent bonds is unequally distributed because one nucleus has a stronger attraction for the electrons than the other has.

Refer to the figure below. Which diagram represents magnesium (Mg; atomic number 12)?

A(n) _______ atom has 7 neutrons and a mass number of 15.

Refer to the two balanced chemical equations below. (1) CH4 + 2 O2  CO2 + 2 H2O + 890 kJ (2) C3H8 + 5 O2  3 CO2 + 4 H2O + 2,220 kJ According to the information given, reaction 2 involves a _______ change in energy than reaction 1.

Hydrogen bonds

The number of different natural elements found in the universe is closest to

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

The ball-and-stick structure of methane (CH₄) shows that

Refer to the two balanced chemical equations below. (1) CH₄ + 2 O₂  CO₂ + 2 H₂O + 890 kJ (2) C₃H₈ + 5 O₂  3 CO₂ + 4 H₂O + 2,220 kJ According to the information given, reaction 2 involves a _______ change in energy than reaction 1.