The isotope 201Th is used in the diagnosis of heart disease. It has a first-order rate constant, k, of 9.49 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 hF1F1F1S1F1F1F101. What is the half-life for 201Th?

A) 73 hr B) 0.014 hr C) 9.49 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 hr D) 7.3 hr E) 1.4 hr A) 73 hr B) 0.014 hr C) 9.49 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F103 hr D) 7.3 hr E) 1.4 hr

Hydroxyapatite, which is a component of tooth enamel, is very insoluble in water. For the following reaction, Ksp F1F1F1S1F1F1F10 2.3 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1059. What is the molar concentration of Ca5(PO4)3F1F1F1S1F1F1F10 when the pH of the mouth is 4.0?

A) 2.3 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1049 M B) 2.3 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1059 M C) 2.3 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1055 M D) 2.3 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1063 M E) 0, teeth don't dissolve! A) 2.3 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1049 M B) 2.3 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1059 M C) 2.3 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1055 M D) 2.3 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F1063 M E) 0, teeth don't dissolve!

Calcium carbonate is used to form exoskeletons. It has a solubility-product constant of 5.0 F1F1F1S1F1F1F10 10 F1F1F1S1F1F1F10 9. What is the molar concentration of calcium ions in a saturated solution of calcium carbonate?

A) 2.5 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F109 M B) 7.1 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F105 M C) 3.5 F1F1F1S1F1F1F10 10 F1F1F1S1F1F1F105 M D) 5.0 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F109 M E) 4.7 F1F1F1S1F1F1F10 10 F1F1F1S1F1F1F107 M A) 2.5 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F109 M B) 7.1 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F105 M C) 3.5 F1F1F1S1F1F1F10 10 F1F1F1S1F1F1F105 M D) 5.0 F1F1F1S1F1F1F10 10F1F1F1S1F1F1F109 M E) 4.7 F1F1F1S1F1F1F10 10 F1F1F1S1F1F1F107 M

Radioactive tritium, 3H, is used as a tracer in many biological experiments. It decays by F1F1F1S1F1F1F10 emission. What is the product of this decay?

A) (3He) B) (4He) C) (2H) D) (14 C) E) (2H). A) (3He) B) (4He) C) (2H) D) (14 C) E) (2H).

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

Enzymes in plants convert nitrate into ammonia. The unbalanced half-reaction equation is given below. What is the stoichiometric coefficient of the electrons, e^, in the balanced reaction equation?

(Multiple Choice)

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Question 61

Superoxide dismutase is an enzyme that converts the reactive superoxide ion to hydrogen peroxide. Based on the equation for the reaction shown below, identify the reducing and oxidizing agents in the reaction.

(Essay)

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Question 62

The isotope ²⁰¹Th is used in the diagnosis of heart disease. It has a first-order rate constant, k, of 9.49  10^³ h^¹. What is the half-life for ²⁰¹Th?

(Multiple Choice)

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Question 63

Hydroxyapatite, which is a component of tooth enamel, is very insoluble in water. For the following reaction, K_sp  2.3  10^⁵⁹. What is the molar concentration of Ca₅(PO₄)₃^ when the pH of the mouth is 4.0?

(Multiple Choice)

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Question 64

Plants convert nitrogen into ammonia. This biological nitrogen fixation is effected by enzymes called nitrogenases. The enzymes assist in the transfer of electrons. The unbalanced reaction equation is What is the stoichiometric coefficient for ammonia in the balanced reaction equation?

(Multiple Choice)

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Question 65

A radioactive isotope that emits the shortest range particles and therefore would be a good choice for implantation therapy most likely decays via ________

(Multiple Choice)

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Question 66

Which metal, by the number of atoms, is most abundant in the human body?

(Multiple Choice)

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Question 67

Thallium-201 is used in cardiac imaging. It decays by electron capture. What isotope is produced when thallium-201 captures an electron?

(Short Answer)

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Question 68

Lithium is used in the treatment of which disease?

(Multiple Choice)

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Question 69

Ion channels in cell membranes control selective transport of ions based on what property(ies)?

(Multiple Choice)

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Question 70

Which statement describing the mechanisms by which sodium ions pass through cell membranes is not correct?

(Multiple Choice)

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Question 71

Nitrogen is a major essential element in the human body. Which biomolecules incorporate nitrogen?

(Short Answer)

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Question 72

Adding fluoride ions to toothpaste and drinking water converts the mineral in tooth enamel, hydroxyapatite, to fluoroapatite. This conversion is beneficial in preventing tooth decay because fluoroapatite ________

(Multiple Choice)

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Question 73

Cell membranes are formed by ________

(Multiple Choice)

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Question 74

Calcium carbonate is used to form exoskeletons. It has a solubility-product constant of 5.0  10 ^ ⁹. What is the molar concentration of calcium ions in a saturated solution of calcium carbonate?

(Multiple Choice)

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Question 75

Hydroxyapatite, which is a component of tooth enamel, is very insoluble in water. For the following reaction, K_sp  2.3  10^⁵⁹. What is the molar concentration of Ca₅(PO₄)₃^ when the pH of the mouth is 4.0?

(Short Answer)

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Question 76

Different concentrations of ions on either side of a cell membrane constitute a concentration cell, which is described by the Nernst equation given below. A cell must expend energy to maintain this concentration gradient by moving ions from one side of the membrane to the other. How much energy must be expended to transport 1 mole of sodium ions 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 37C (body temperature)? (Given: ,  2.71 V; F  96,485 C; 1 J  1 C V; R  8.315 J / (mol K)) E  E - InQ

(Short Answer)

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Question 77

Which of the following elements, by mass, is the most abundant in the universe?

(Multiple Choice)

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Question 78

The nucleus of a cell has a pH of approximately 7.3. What is the molar concentration of hydroxide in the nucleus of a cell?

(Multiple Choice)

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Question 79

Radioactive tritium, ³H, is used as a tracer in many biological experiments. It decays by  emission. What is the product of this decay?

(Multiple Choice)

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Question 80

Showing 61 - 80 of 96

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

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

Superoxide dismutase is an enzyme that converts the reactive superoxide ion to hydrogen peroxide. Based on the equation for the reaction shown below, identify the reducing and oxidizing agents in the reaction.

The isotope 201Th is used in the diagnosis of heart disease. It has a first-order rate constant, k, of 9.49  103 h1. What is the half-life for 201Th?

Hydroxyapatite, which is a component of tooth enamel, is very insoluble in water. For the following reaction, Ksp  2.3  1059. What is the molar concentration of Ca5(PO4)3 when the pH of the mouth is 4.0?

Plants convert nitrogen into ammonia. This biological nitrogen fixation is effected by enzymes called nitrogenases. The enzymes assist in the transfer of electrons. The unbalanced reaction equation is What is the stoichiometric coefficient for ammonia in the balanced reaction equation?

A radioactive isotope that emits the shortest range particles and therefore would be a good choice for implantation therapy most likely decays via ________

Which metal, by the number of atoms, is most abundant in the human body?

Thallium-201 is used in cardiac imaging. It decays by electron capture. What isotope is produced when thallium-201 captures an electron?

Lithium is used in the treatment of which disease?

Ion channels in cell membranes control selective transport of ions based on what property(ies)?

Which statement describing the mechanisms by which sodium ions pass through cell membranes is not correct?

Nitrogen is a major essential element in the human body. Which biomolecules incorporate nitrogen?

Adding fluoride ions to toothpaste and drinking water converts the mineral in tooth enamel, hydroxyapatite, to fluoroapatite. This conversion is beneficial in preventing tooth decay because fluoroapatite ________

Cell membranes are formed by ________

Calcium carbonate is used to form exoskeletons. It has a solubility-product constant of 5.0  10  9. What is the molar concentration of calcium ions in a saturated solution of calcium carbonate?

Hydroxyapatite, which is a component of tooth enamel, is very insoluble in water. For the following reaction, Ksp  2.3  1059. What is the molar concentration of Ca5(PO4)3 when the pH of the mouth is 4.0?

Which of the following elements, by mass, is the most abundant in the universe?

The nucleus of a cell has a pH of approximately 7.3. What is the molar concentration of hydroxide in the nucleus of a cell?

Radioactive tritium, 3H, is used as a tracer in many biological experiments. It decays by  emission. What is the product of this decay?

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

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Enzymes in plants convert nitrate into ammonia. The unbalanced half-reaction equation is given below. What is the stoichiometric coefficient of the electrons, e^, in the balanced reaction equation?

The isotope ²⁰¹Th is used in the diagnosis of heart disease. It has a first-order rate constant, k, of 9.49  10^³ h^¹. What is the half-life for ²⁰¹Th?

Hydroxyapatite, which is a component of tooth enamel, is very insoluble in water. For the following reaction, K_sp  2.3  10^⁵⁹. What is the molar concentration of Ca₅(PO₄)₃^ when the pH of the mouth is 4.0?

Calcium carbonate is used to form exoskeletons. It has a solubility-product constant of 5.0  10 ^ ⁹. What is the molar concentration of calcium ions in a saturated solution of calcium carbonate?

Hydroxyapatite, which is a component of tooth enamel, is very insoluble in water. For the following reaction, K_sp  2.3  10^⁵⁹. What is the molar concentration of Ca₅(PO₄)₃^ when the pH of the mouth is 4.0?

Radioactive tritium, ³H, is used as a tracer in many biological experiments. It decays by  emission. What is the product of this decay?