Question 1

Selenium can substitute for sulfur in the amino acid cysteine to make the amino acid selenocysteine because ________

Accepted Answer

A) sulfur and selenium both begin with s. 
B) their atomic symbols are similar. 
C) both have about the same atomic radius. 
D) both have the same valence electron configuration. 
E) both have about the same ionization potential. 
A) sulfur and selenium both begin with s. 
B) their atomic symbols are similar. 
C) both have about the same atomic radius. 
D) both have the same valence electron configuration. 
E) both have about the same ionization potential.

Question 2

Different concentrations of ions on either side of a cell membrane constitute a concentration cell, which is described by the Nernst equation given below. What is the electrochemical potential across a membrane when the sodium ion concentration is 0.10 M on one side of the membrane and 0.010 M on the other side, and the temperature is 37F1F1F1S1F1F1F10C (body temperature)?
(Given: NaF1F1F1S1F1F1F10 F1F1F1S1F1F1F10 eF1F1F1S1F1F1F10 F1F1F1S1F1F1F10F1F1F1S1F1F1F10a,    F1F1F1S1F1F1F10 F1F1F1S1F1F1F102.71 V; F F1F1F1S1F1F1F10 96,485 C; 1 J F1F1F1S1F1F1F10 1 C V; R F1F1F1S1F1F1F10 8.315 J / (molK))
E F1F1F1S1F1F1F10 EF1F1F1S1F1F1F10 -   InQ

Accepted Answer

Question 3

Which element may contribute to sudden infant death syndrome (SIDS), as it is used as a fire retardant in mattresses?

Accepted Answer

A) bismuth 
B) chromium 
C) boron 
D) aluminum 
E) antimony 
A) bismuth 
B) chromium 
C) boron 
D) aluminum 
E) antimony

Question 4

Radioactive 90Sr can substitute for ________ in the human body.

Accepted Answer

A) NaF1F1F1S1F1F1F10 
B) Ca2F1F1F1S1F1F1F10 
C) KF1F1F1S1F1F1F10 
D) S2F1F1F1S1F1F1F10 
E) Se2F1F1F1S1F1F1F10 
A) NaF1F1F1S1F1F1F10 
B) Ca2F1F1F1S1F1F1F10 
C) KF1F1F1S1F1F1F10 
D) S2F1F1F1S1F1F1F10 
E) Se2F1F1F1S1F1F1F10

Question 5

Fluoride is added to toothpastes and drinking water to inhibit tooth decay. What does fluoride do that makes it effective in inhibiting tooth decay?

Accepted Answer

Tooth enamel is composed of a mineral ca

Question 6

Why are some elements in the human body considered to be nonessential?

Accepted Answer

These elements appear to serve

Question 7

Pacemakers implanted in the chests of patients with certain heart conditions are powered by a lithium/iodine PVP battery, where PVP represents polyvinylpyridine. The cell reaction and standard cell potential are given below. The standard reduction potential for Li/LiF1F1F1S1F1F1F10 is F1F1F1S1F1F1F103.05 V. What is the standard reduction potential for the iodine PVP half-reaction?   
3.59 V

Accepted Answer

A) (F1F1F1S1F1F1F101.50 V) 
B) (F1F1F1S1F1F1F10 6.64 V) 
C) (F1F1F1S1F1F1F10 0.54 V) 
D) (F1F1F1S1F1F1F10 6.64 V) 
E) (F1F1F1S1F1F1F10 0.54 V) 
A) (F1F1F1S1F1F1F101.50 V) 
B) (F1F1F1S1F1F1F10 6.64 V) 
C) (F1F1F1S1F1F1F10 0.54 V) 
D) (F1F1F1S1F1F1F10 6.64 V) 
E) (F1F1F1S1F1F1F10 0.54 V)

Question 8

Tooth enamel is composed of the mineral hydroxyapatite. It is essentially insoluble in water with Ksp F1F1F1S1F1F1F10 2.3 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1059, but it reacts with weak acids in the mouth as described by one of the reaction equations below. You can determine the equilibrium constant, K, for this reaction from Ksp and Kw (the equilibrium constant for water autoionization). How do you do this?

Accepted Answer

A) K F1F1F1S1F1F1F10 KwKsp 
B) K F1F1F1S1F1F1F10 Kw /Ksp 
C) K F1F1F1S1F1F1F10 Ksp /Kw 
D) K F1F1F1S1F1F1F10 Kw F1F1F1S1F1F1F10 Ksp 
E) K F1F1F1S1F1F1F10 Kw F1F1F1S1F1F1F10 Ksp 
A) K F1F1F1S1F1F1F10 KwKsp 
B) K F1F1F1S1F1F1F10 Kw /Ksp 
C) K F1F1F1S1F1F1F10 Ksp /Kw 
D) K F1F1F1S1F1F1F10 Kw F1F1F1S1F1F1F10 Ksp 
E) K F1F1F1S1F1F1F10 Kw F1F1F1S1F1F1F10 Ksp

Question 9

The concentration of an ultratrace essential element in the body is less than ________ per gram of body mass.

Accepted Answer

A) 1 g 
B) 10 mg 
C) 1 mg 
D) 10 F1F1F1S1F1F1F10g 
E) 1 F1F1F1S1F1F1F10g 
A) 1 g 
B) 10 mg 
C) 1 mg 
D) 10 F1F1F1S1F1F1F10g 
E) 1 F1F1F1S1F1F1F10g

Question 10

Hearing aid batteries utilize a zinc/air electrochemical cell. The reduction half-reactions and standard reduction potentials for this cell are given below. Write the balanced reaction equation for the cell and report the sum of the stoichiometric coefficients.   F1F1F1S1F1F1F101.249 V   F1F1F1S1F1F1F100.401 V

Accepted Answer

A) 4 
B) 5 
C) 6 
D) 7 
E) 8 
A) 4 
B) 5 
C) 6 
D) 7 
E) 8

Question 11

Enzymes in plants convert nitrate into ammonia. The unbalanced half-reaction equation is given below. What is the stoichiometric coefficient of the nitrite ion in the balanced reaction equation?

Accepted Answer

A) 0 
B) 1 
C) 2 
D) 3 
E) 4 
A) 0 
B) 1 
C) 2 
D) 3 
E) 4

Question 12

Plants convert nitrogen into ammonia. This biological nitrogen fixation is effected by enzymes called nitrogenases. The enzymes assist in the transfer of electrons. Balance this reaction equation.

Accepted Answer

The answer of Plants convert nitrogen into ammonia. This biological...

Question 13

Draw two possible Lewis structures of the cation BiOF1F1F1S1F1F1F10, which is found in some over-the-counter antacids. Which one has the formal charge of F1F1F1S1F1F1F101 on the more electropositive atom?

Accepted Answer

Bi is the

Question 14

Hearing aid batteries utilize a zinc/air electrochemical cell. The reduction half-reactions and standard reduction potentials for this cell are given below. What species are oxidized and reduced in the cell reaction?   F1F1F1S1F1F1F101.249 V   F1F1F1S1F1F1F100.401 V

Accepted Answer

A) Oxygen is reduced and zinc is oxidized. 
B) Zinc is reduced and oxygen is oxidized. 
C) Zinc hydroxide is reduced and oxygen is oxidized. 
D) Zinc hydroxide is reduced and hydroxide is oxidized. 
E) Water is reduced and zinc is oxidized. 
A) Oxygen is reduced and zinc is oxidized. 
B) Zinc is reduced and oxygen is oxidized. 
C) Zinc hydroxide is reduced and oxygen is oxidized. 
D) Zinc hydroxide is reduced and hydroxide is oxidized. 
E) Water is reduced and zinc is oxidized.

Question 15

The isotope 18F is used in a range of radio imaging applications. It has a first-order rate constant, k, of 6.30 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 minF1F1F1S1F1F1F101. What is the half-life for 18F?

Accepted Answer

A) 159 min 
B) 110 min 
C) 9.10 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 min 
D) 2.34 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 min 
E) 1,743 min 
A) 159 min 
B) 110 min 
C) 9.10 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 min 
D) 2.34 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 min 
E) 1,743 min

Question 16

The ion found in chlorophyll is ________

Accepted Answer

A) Zn2F1F1F1S1F1F1F10. 
B) Mg2F1F1F1S1F1F1F10. 
C) Ca2F1F1F1S1F1F1F10. 
D) Fe2F1F1F1S1F1F1F10. 
E) Cu2F1F1F1S1F1F1F10. 
A) Zn2F1F1F1S1F1F1F10. 
B) Mg2F1F1F1S1F1F1F10. 
C) Ca2F1F1F1S1F1F1F10. 
D) Fe2F1F1F1S1F1F1F10. 
E) Cu2F1F1F1S1F1F1F10.

Question 17

Why are the radioactive isotopes of cesium and strontium that are produced in nuclear reactors or by the atmospheric testing of nuclear weapons especially dangerous to humans?

Accepted Answer

They have long half-lives and

Question 18

Different concentrations of ions on either side of a cell membrane constitute a concentration cell, which is described by the Nernst equation given below. What is the electrochemical potential across a membrane when the sodium ion concentration is 0.10 M on one side of the membrane and 0.010 M on the other side, and the temperature is 37F1F1F1S1F1F1F10C (body temperature)? (Given:   ,F1F1F1S1F1F1F10F1F1F1S1F1F1F10   F1F1F1S1F1F1F10 F1F1F1S1F1F1F102.71 V; F F1F1F1S1F1F1F10 96,485 C; 1 J F1F1F1S1F1F1F10 1 C V; R F1F1F1S1F1F1F10 8.315 J / (mol K))
E F1F1F1S1F1F1F10 EF1F1F1S1F1F1F10 -   InQ

Accepted Answer

A) 61.5 mV 
B) 26.7 mV 
C) 2.65 V 
D) 2.68 V 
E) 2.98 V 
A) 61.5 mV 
B) 26.7 mV 
C) 2.65 V 
D) 2.68 V 
E) 2.98 V

Question 19

The concentration of a major essential element in the body is greater than ________ per gram of body mass.

Accepted Answer

A) 1 g 
B) 10 mg 
C) 1 mg 
D) 10 F1F1F1S1F1F1F10g 
E) 1 F1F1F1S1F1F1F10g 
A) 1 g 
B) 10 mg 
C) 1 mg 
D) 10 F1F1F1S1F1F1F10g 
E) 1 F1F1F1S1F1F1F10g

Question 20

A patient is injected with a 5.0 F1F1F1S1F1F1F10M solution of gallium citrate containing radioactive gallium-68 for a PET study. The half-life of gallium-68 is 9.4 hr. How long does it take for the activity of this isotope to drop to 1% of its initial value?

Accepted Answer

A) 18 hr 
B) 25 hr 
C) 32 hr 
D) 41 hr 
E) 62 hr 
A) 18 hr 
B) 25 hr 
C) 32 hr 
D) 41 hr 
E) 62 hr

Selenium can substitute for sulfur in the amino acid cysteine to make the amino acid selenocysteine because ________

Which element may contribute to sudden infant death syndrome (SIDS), as it is used as a fire retardant in mattresses?

Radioactive ⁹⁰Sr can substitute for ________ in the human body.

Fluoride is added to toothpastes and drinking water to inhibit tooth decay. What does fluoride do that makes it effective in inhibiting tooth decay?

Why are some elements in the human body considered to be nonessential?

The concentration of an ultratrace essential element in the body is less than ________ per gram of body mass.

Hearing aid batteries utilize a zinc/air electrochemical cell. The reduction half-reactions and standard reduction potentials for this cell are given below. Write the balanced reaction equation for the cell and report the sum of the stoichiometric coefficients. 1.249 V 0.401 V

Enzymes in plants convert nitrate into ammonia. The unbalanced half-reaction equation is given below. What is the stoichiometric coefficient of the nitrite ion in the balanced reaction equation?

Plants convert nitrogen into ammonia. This biological nitrogen fixation is effected by enzymes called nitrogenases. The enzymes assist in the transfer of electrons. Balance this reaction equation.

Draw two possible Lewis structures of the cation BiO^, which is found in some over-the-counter antacids. Which one has the formal charge of 1 on the more electropositive atom?

Hearing aid batteries utilize a zinc/air electrochemical cell. The reduction half-reactions and standard reduction potentials for this cell are given below. What species are oxidized and reduced in the cell reaction? 1.249 V 0.401 V

The isotope ¹⁸F is used in a range of radio imaging applications. It has a first-order rate constant, k, of 6.30  10^³ min^¹. What is the half-life for ¹⁸F?

The ion found in chlorophyll is ________

Why are the radioactive isotopes of cesium and strontium that are produced in nuclear reactors or by the atmospheric testing of nuclear weapons especially dangerous to humans?

The concentration of a major essential element in the body is greater than ________ per gram of body mass.

A patient is injected with a 5.0 M solution of gallium citrate containing radioactive gallium-68 for a PET study. The half-life of gallium-68 is 9.4 hr. How long does it take for the activity of this isotope to drop to 1% of its initial value?

Matter and Energy: The Origin of the Universe

Atoms, Ions, and Molecules: Matter Starts Here

Stoichiometry: Mass, Formulas, and Reactions

Solution Chemistry: The Hydrosphere

Thermochemistry: Energy Changes in Reactions

Properties of Gases: The Air We Breathe

A Quantum Model of Atoms: Waves and Particles

Chemical Bonds: What Makes a Gas a Greenhouse Gas

Molecular Geometry: Shape Determines Function

Intermolecular Forces: The Uniqueness of Water

Solutions: Properties and Behavior

Solids: Crystals, Alloys, and Polymers

Chemical Kinetics: Reactions in the Atmosphere

Chemical Equilibrium: How Much Product Does a Reaction Really Make

Acidbase Equilibria: Proton Transfer in Biological Systems

Additional Aqueous Equilibria: Chemistry and the Oceans

Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

Electrochemistry: The Quest for Clean Energy

Nuclear Chemistry: Applications to Energy and Medicine

Organic and Biological Molecules: the Compounds of Life

Transition Metals: Biological and Medical Applications

Filters

Exam 21: The Main Group Elements: Life and the Periodic Table

Selenium can substitute for sulfur in the amino acid cysteine to make the amino acid selenocysteine because ________

Which element may contribute to sudden infant death syndrome (SIDS), as it is used as a fire retardant in mattresses?

Radioactive 90Sr can substitute for ________ in the human body.

Fluoride is added to toothpastes and drinking water to inhibit tooth decay. What does fluoride do that makes it effective in inhibiting tooth decay?

Why are some elements in the human body considered to be nonessential?

The concentration of an ultratrace essential element in the body is less than ________ per gram of body mass.

Hearing aid batteries utilize a zinc/air electrochemical cell. The reduction half-reactions and standard reduction potentials for this cell are given below. Write the balanced reaction equation for the cell and report the sum of the stoichiometric coefficients. 1.249 V 0.401 V

Enzymes in plants convert nitrate into ammonia. The unbalanced half-reaction equation is given below. What is the stoichiometric coefficient of the nitrite ion in the balanced reaction equation?

Plants convert nitrogen into ammonia. This biological nitrogen fixation is effected by enzymes called nitrogenases. The enzymes assist in the transfer of electrons. Balance this reaction equation.

Draw two possible Lewis structures of the cation BiO, which is found in some over-the-counter antacids. Which one has the formal charge of 1 on the more electropositive atom?

Hearing aid batteries utilize a zinc/air electrochemical cell. The reduction half-reactions and standard reduction potentials for this cell are given below. What species are oxidized and reduced in the cell reaction? 1.249 V 0.401 V

The isotope 18F is used in a range of radio imaging applications. It has a first-order rate constant, k, of 6.30  103 min1. What is the half-life for 18F?

The ion found in chlorophyll is ________

Why are the radioactive isotopes of cesium and strontium that are produced in nuclear reactors or by the atmospheric testing of nuclear weapons especially dangerous to humans?

The concentration of a major essential element in the body is greater than ________ per gram of body mass.

A patient is injected with a 5.0 M solution of gallium citrate containing radioactive gallium-68 for a PET study. The half-life of gallium-68 is 9.4 hr. How long does it take for the activity of this isotope to drop to 1% of its initial value?

Matter and Energy: The Origin of the Universe

Atoms, Ions, and Molecules: Matter Starts Here

Stoichiometry: Mass, Formulas, and Reactions

Solution Chemistry: The Hydrosphere

Thermochemistry: Energy Changes in Reactions

Properties of Gases: The Air We Breathe

A Quantum Model of Atoms: Waves and Particles

Chemical Bonds: What Makes a Gas a Greenhouse Gas

Molecular Geometry: Shape Determines Function

Intermolecular Forces: The Uniqueness of Water

Solutions: Properties and Behavior

Solids: Crystals, Alloys, and Polymers

Chemical Kinetics: Reactions in the Atmosphere

Chemical Equilibrium: How Much Product Does a Reaction Really Make

Acidbase Equilibria: Proton Transfer in Biological Systems

Additional Aqueous Equilibria: Chemistry and the Oceans

Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

Electrochemistry: The Quest for Clean Energy

Nuclear Chemistry: Applications to Energy and Medicine

Organic and Biological Molecules: the Compounds of Life

Transition Metals: Biological and Medical Applications

Filters

Radioactive ⁹⁰Sr can substitute for ________ in the human body.

Draw two possible Lewis structures of the cation BiO^, which is found in some over-the-counter antacids. Which one has the formal charge of 1 on the more electropositive atom?

The isotope ¹⁸F is used in a range of radio imaging applications. It has a first-order rate constant, k, of 6.30  10^³ min^¹. What is the half-life for ¹⁸F?