Question 1

During chemical evolution,which of the following occurred in the molecules involved?

Accepted Answer

A) Entropy decreased while potential energy increased. 
B) Entropy increased while potential energy increased. 
C) Entropy stayed constant while potential energy increased. 
A) Entropy decreased while potential energy increased. 
B) Entropy increased while potential energy increased. 
C) Entropy stayed constant while potential energy increased. A

Question 2

In the Gibbs free-energy relationship,why is the T term necessary?

Accepted Answer

A) The free-energy change caused by a change in entropy is a function of temperature. 
B) The free-energy change caused by a change in potential energy is a function of temperature. 
C) The free-energy change caused by a change in electrical charge is a function of temperature. 
A) The free-energy change caused by a change in entropy is a function of temperature. 
B) The free-energy change caused by a change in potential energy is a function of temperature. 
C) The free-energy change caused by a change in electrical charge is a function of temperature. A

Question 3

The cities of Portland,Oregon,and Minneapolis,Minnesota,are at about the same latitude,but Minneapolis has much hotter summers and much colder winters than Portland does.Why? (Portland is near the Pacific Ocean;Minneapolis is near a number of large lakes. )

Accepted Answer

A) They are not at exactly the same latitude. 
B) The ocean is so large that it has a highly moderating influence on temperature. 
C) Freshwater is more likely to freeze than salt water. 
D) Minneapolis is much windier,due to its location in the middle of a continent. 
A) They are not at exactly the same latitude. 
B) The ocean is so large that it has a highly moderating influence on temperature. 
C) Freshwater is more likely to freeze than salt water. 
D) Minneapolis is much windier,due to its location in the middle of a continent. B

Question 4

When the atoms involved in a covalent bond have the same electronegativity,what type of bond results?

Accepted Answer

A) an ionic bond 
B) a hydrogen bond 
C) a nonpolar covalent bond 
D) a polar covalent bond 
A) an ionic bond 
B) a hydrogen bond 
C) a nonpolar covalent bond 
D) a polar covalent bond

Question 5

Do all human body fluids have the same pH? If not,rank,in the order of low to high,the pH of blood,urine,and stomach acid.

Accepted Answer

A) Yes.Blood,urine,and stomach acid all have the same pH. 
B) No.The pH ranking from low to high is stomach acid,blood,urine. 
C) No.The pH ranking from low to high is urine,blood,stomach acid. 
D) No.The pH ranking from low to high is stomach acid,urine,blood. 
A) Yes.Blood,urine,and stomach acid all have the same pH. 
B) No.The pH ranking from low to high is stomach acid,blood,urine. 
C) No.The pH ranking from low to high is urine,blood,stomach acid. 
D) No.The pH ranking from low to high is stomach acid,urine,blood.

Question 6

How many electrons are involved in a double covalent bond?

Accepted Answer

A) one 
B) two 
C) three 
D) four 
A) one 
B) two 
C) three 
D) four

Question 7

You need to write down information about a molecule,but need to indicate only which atoms it contains and how many of each.Which representation would work best?

Accepted Answer

A) molecular formula 
B) structural formula 
C) ball-and-stick model 
D) space-filling model 
A) molecular formula 
B) structural formula 
C) ball-and-stick model 
D) space-filling model

Question 8

While water has many exceptional and useful properties,which is the rarest property among compounds?

Accepted Answer

A) Water is a solvent. 
B) Solid water is less dense than liquid water. 
C) Water has a high heat capacity. 
D) Water has surface tension. 
A) Water is a solvent. 
B) Solid water is less dense than liquid water. 
C) Water has a high heat capacity. 
D) Water has surface tension.

Question 9

Why would the spontaneous formation of formaldehyde and hydrogen cyanide not take place on Earth today as much as on the prebiotic Earth?

Accepted Answer

A) Microorganisms break these down immediately. 
B) The Sun has changed its output. 
C) Atmospheric conditions on Earth,such as the presence of oxygen,have changed. 
A) Microorganisms break these down immediately. 
B) The Sun has changed its output. 
C) Atmospheric conditions on Earth,such as the presence of oxygen,have changed.

Question 10

If an atom has a charge of +1,which of the following must be true?

Accepted Answer

A) It has two more protons than neutrons. 
B) It has the same number of protons as electrons. 
C) It has one more electron than it does protons. 
D) It has one more proton than it does electrons. 
A) It has two more protons than neutrons. 
B) It has the same number of protons as electrons. 
C) It has one more electron than it does protons. 
D) It has one more proton than it does electrons.

Question 11

What holds electrons in a covalent bond?

Accepted Answer

A) It is the fact that two electrons are paired in the same orbital. 
B) The electron sharing that occurs makes the atoms involved smaller and more compact. 
C) An increase in potential energy,caused by electrical repulsion of the electrons in the bond,holds the electrons. 
D) The negative charges on the electrons are attracted by the positive charges on both nuclei. 
A) It is the fact that two electrons are paired in the same orbital. 
B) The electron sharing that occurs makes the atoms involved smaller and more compact. 
C) An increase in potential energy,caused by electrical repulsion of the electrons in the bond,holds the electrons. 
D) The negative charges on the electrons are attracted by the positive charges on both nuclei.

Question 12

Carbon is an important element for biology because _____.

Accepted Answer

A) of the variety of carbon skeletons and functional groups that can be built on them 
B) it has very high electronegativity and forms highly stable bonds 
C) carbon is so rare,organisms conserve it highly 
D) it has the ability to form six covalent bonds 
A) of the variety of carbon skeletons and functional groups that can be built on them 
B) it has very high electronegativity and forms highly stable bonds 
C) carbon is so rare,organisms conserve it highly 
D) it has the ability to form six covalent bonds

Question 13

A solution with a pH of 5 has how many more protons in it than a solution with a pH of 7?

Accepted Answer

A) 5 times 
B) 10 times 
C) 100 times 
D) 1000 times 
A) 5 times 
B) 10 times 
C) 100 times 
D) 1000 times

Question 14

Can the atomic mass of an element change?

Accepted Answer

A) No,it is fixed.If it changes at all then you have formed a different element. 
B) Yes.Adding or losing electrons will substantially change the atomic mass. 
C) Yes.Adding or losing protons will change the atomic mass without forming a different element. 
D) Yes.Adding or losing neutrons will change the atomic mass without forming a different element. 
A) No,it is fixed.If it changes at all then you have formed a different element. 
B) Yes.Adding or losing electrons will substantially change the atomic mass. 
C) Yes.Adding or losing protons will change the atomic mass without forming a different element. 
D) Yes.Adding or losing neutrons will change the atomic mass without forming a different element.

Question 15

When are atoms most stable?

Accepted Answer

A) when they have the fewest possible valence electrons 
B) when they have the maximum number of unpaired electrons 
C) when all of the electron orbitals in the valence shell are filled 
D) when all electrons are paired 
A) when they have the fewest possible valence electrons 
B) when they have the maximum number of unpaired electrons 
C) when all of the electron orbitals in the valence shell are filled 
D) when all electrons are paired

Question 16

Water has a high specific heat because of the _____.

Accepted Answer

A) polar covalent bond formed between the oxygen and a hydrogen of a single water molecule 
B) ionic bonds formed between the hydrogen of one water molecule and the oxygen of another water molecule 
C) hydrogen bond formed between the hydrogen of one water molecule and the oxygen of another water molecule 
D) covalent bond formed between the hydrogen of one water molecule and the oxygen of another water molecule 
A) polar covalent bond formed between the oxygen and a hydrogen of a single water molecule 
B) ionic bonds formed between the hydrogen of one water molecule and the oxygen of another water molecule 
C) hydrogen bond formed between the hydrogen of one water molecule and the oxygen of another water molecule 
D) covalent bond formed between the hydrogen of one water molecule and the oxygen of another water molecule

Question 17

Elements found on the left side of the periodic table contain outer shells that are _____;these elements tend to form _____ in solution.

Accepted Answer

A) almost empty;cations 
B) almost empty;anions 
C) almost full;cations 
D) almost full;anions 
A) almost empty;cations 
B) almost empty;anions 
C) almost full;cations 
D) almost full;anions

Question 18

Silicon's atomic number is 14;in the periodic table it is directly beneath carbon.Silicon is abundant in the Earth's crust,yet,unlike C,N,O,and H,silicon is not a common element in organisms.What about the atomic structure of silicon probably accounts for this?

Accepted Answer

A) The nucleus of silicon is probably too small to form long chains of Si-Si molecules (analogous to long chains of carbon molecules). 
B) The nucleus of silicon is probably too big to form long chains of Si-Si molecules (analogous to long chains of carbon molecules). 
C) Silicon only has three valence electrons,so it can make fewer covalent bonds than carbon. 
D) Silicon is too electronegative to be an element common in living organisms. 
A) The nucleus of silicon is probably too small to form long chains of Si-Si molecules (analogous to long chains of carbon molecules). 
B) The nucleus of silicon is probably too big to form long chains of Si-Si molecules (analogous to long chains of carbon molecules). 
C) Silicon only has three valence electrons,so it can make fewer covalent bonds than carbon. 
D) Silicon is too electronegative to be an element common in living organisms.

Question 19

Consider the following reaction at equilibrium:
CO₂ + H₂O ↔ H₂CO₃.What would be the effect of adding additional H₂CO₃?

Accepted Answer

A) It would drive the equilibrium dynamics to the right. 
B) It would drive the equilibrium dynamics to the left. 
C) Nothing would happen,because the reactants and products are in equilibrium. 
D) The amounts of CO₂ and H₂O would decrease. 
A) It would drive the equilibrium dynamics to the right. 
B) It would drive the equilibrium dynamics to the left. 
C) Nothing would happen,because the reactants and products are in equilibrium. 
D) The amounts of CO₂ and H₂O would decrease.

Question 20

An atom has four electrons in its valence shell.What types of covalent bonds is it capable of forming?

Accepted Answer

A) single,double,or triple 
B) single and double only 
C) four single bonds only 
D) two double bonds only 
A) single,double,or triple 
B) single and double only 
C) four single bonds only 
D) two double bonds only

Exam 2: Water and Carbon: the Chemical Basis of Life

During chemical evolution,which of the following occurred in the molecules involved?

In the Gibbs free-energy relationship,why is the T term necessary?

The cities of Portland,Oregon,and Minneapolis,Minnesota,are at about the same latitude,but Minneapolis has much hotter summers and much colder winters than Portland does.Why? (Portland is near the Pacific Ocean;Minneapolis is near a number of large lakes. )

When the atoms involved in a covalent bond have the same electronegativity,what type of bond results?

Do all human body fluids have the same pH? If not,rank,in the order of low to high,the pH of blood,urine,and stomach acid.

How many electrons are involved in a double covalent bond?

You need to write down information about a molecule,but need to indicate only which atoms it contains and how many of each.Which representation would work best?

While water has many exceptional and useful properties,which is the rarest property among compounds?

Why would the spontaneous formation of formaldehyde and hydrogen cyanide not take place on Earth today as much as on the prebiotic Earth?

If an atom has a charge of +1,which of the following must be true?

What holds electrons in a covalent bond?

Carbon is an important element for biology because _____.

A solution with a pH of 5 has how many more protons in it than a solution with a pH of 7?

Can the atomic mass of an element change?

When are atoms most stable?

Water has a high specific heat because of the _____.

Elements found on the left side of the periodic table contain outer shells that are _____;these elements tend to form _____ in solution.

Silicon's atomic number is 14;in the periodic table it is directly beneath carbon.Silicon is abundant in the Earth's crust,yet,unlike C,N,O,and H,silicon is not a common element in organisms.What about the atomic structure of silicon probably accounts for this?

Consider the following reaction at equilibrium: CO₂ + H₂O ↔ H₂CO₃.What would be the effect of adding additional H₂CO₃?

An atom has four electrons in its valence shell.What types of covalent bonds is it capable of forming?

Biology and the Tree of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Lipids, membranes, and the First Cells

Inside the Cell

Cell-Cell Interactions

Cellular Respiration and Fermentation

Photosynthesis

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

Analyzing and Engineering Genes

Genomics

Principles of Development

An Introduction to Animal Development

An Introduction to Plant Development

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Protists

Green Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, signals, and Responses

Plant Reproduction

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Electrical Signals in Animals

Animal Sensory Systems and Movement

Chemical Signals in Animals

Animal Reproduction

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Ecosystems

Biodiversity and Conservation Biology

Filters

Elements found on the left side of the periodic table contain outer shells that are _;these elements tend to form _ in solution.