Question 1

Can the atomic mass of an element vary?

Accepted Answer

A)  No, it is fixed; otherwise a new element will be formed. 
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; otherwise a new element will be formed. 
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 2

What coefficients must be placed in the following blanks so that all atoms are accounted for in the products?
C₆H₁₂O₆ → ________ C₂H₆O + ________ CO₂

Accepted Answer

A)  2; 1 
B)  3; 1 
C)  1; 3 
D)  2; 2 
A)  2; 1 
B)  3; 1 
C)  1; 3 
D)  2; 2

Question 3

Nitrogen (N)is more electronegative than hydrogen (H). Which of the following is a correct statement about the atoms in ammonia (NH₃)?

Accepted Answer

A)  Each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative charge. 
B)  Ammonia has an overall positive charge. 
C)  Ammonia has an overall negative charge. 
D)  The nitrogen atom has a partial positive charge; each hydrogen atom has a partial negative charge. 
A)  Each hydrogen atom has a partial positive charge; the nitrogen atom has a partial negative charge. 
B)  Ammonia has an overall positive charge. 
C)  Ammonia has an overall negative charge. 
D)  The nitrogen atom has a partial positive charge; each hydrogen atom has a partial negative charge.

Question 4

Atoms have no electric charge because they have ________.

Accepted Answer

A)  uncharged neutrons in their nuclei 
B)  an equal number of protons and neutrons 
C)  an equal number of protons and electrons 
D)  an equal number of charged and uncharged subatomic particles 
A)  uncharged neutrons in their nuclei 
B)  an equal number of protons and neutrons 
C)  an equal number of protons and electrons 
D)  an equal number of charged and uncharged subatomic particles

Question 5

A covalent chemical bond is one in which ________.

Accepted Answer

A)  electrons are removed from one atom and transferred to another atom so that the two atoms become oppositely charged 
B)  protons and neutrons are shared by two atoms so as to satisfy the requirements of both atoms 
C)  outer-shell electrons of two atoms are shared so as to satisfactorily fill their respective orbitals 
D)  outer-shell electrons of one atom are transferred to fill the inner electron shell of another atom 
A)  electrons are removed from one atom and transferred to another atom so that the two atoms become oppositely charged 
B)  protons and neutrons are shared by two atoms so as to satisfy the requirements of both atoms 
C)  outer-shell electrons of two atoms are shared so as to satisfactorily fill their respective orbitals 
D)  outer-shell electrons of one atom are transferred to fill the inner electron shell of another atom

Question 6

The atomic number of chlorine is 17. The atomic number of magnesium is 12. What is the formula for magnesium chloride?

Accepted Answer

A)  MgCl 
B)  MgCl₂ 
C)  Mg₂Cl 
D)  MgCl₃ 
A)  MgCl 
B)  MgCl₂ 
C)  Mg₂Cl 
D)  MgCl₃

Question 7

Elements ⁷²Zn, ⁷⁵As, and ⁷⁴Ge have the ________.

Accepted Answer

A)  same number of protons 
B)  same number of protons and electrons 
C)  same number of neutrons 
D)  same number of neutrons and electrons 
A)  same number of protons 
B)  same number of protons and electrons 
C)  same number of neutrons 
D)  same number of neutrons and electrons

Question 8

In the term trace element, the adjective trace means that

Accepted Answer

A)  the element is required in very small amounts. 
B)  the element can be used as a label to trace atoms through an organism's metabolism. 
C)  the element is very rare on Earth. 
D)  the element enhances health but is not essential for the organism's long-term survival. 
A)  the element is required in very small amounts. 
B)  the element can be used as a label to trace atoms through an organism's metabolism. 
C)  the element is very rare on Earth. 
D)  the element enhances health but is not essential for the organism's long-term survival.

Question 9

In the following structure where A and B represent two different elements, the valency of A is ________ and B is ________.

Accepted Answer

A)  one; three 
B)  one; five 
C)  three; five 
D)  eight; eight 
A)  one; three 
B)  one; five 
C)  three; five 
D)  eight; eight

Question 10

Refer to the following figure (first three rows of the periodic table) to answer the questions below.
  
-What element does not prefer to react with other elements?

Accepted Answer

A)  hydrogen 
B)  helium 
C)  beryllium 
D)  both hydrogen and beryllium 
A)  hydrogen 
B)  helium 
C)  beryllium 
D)  both hydrogen and beryllium

Question 11

Refer to the following figure to answer the questions below.
  
-Based on electron configuration, which of the elements in the figure would exhibit a chemical behavior most like that of oxygen?

Accepted Answer

A)  carbon 
B)  nitrogen 
C)  sulfur 
D)  phosphorus 
A)  carbon 
B)  nitrogen 
C)  sulfur 
D)  phosphorus

Question 12

The reactivity of an atom arises from

Accepted Answer

A)  the average distance of the outermost electron shell from the nucleus. 
B)  the existence of unpaired electrons in the valence shell. 
C)  the sum of the potential energies of all the electron shells. 
D)  the potential energy of the valence shell. 
A)  the average distance of the outermost electron shell from the nucleus. 
B)  the existence of unpaired electrons in the valence shell. 
C)  the sum of the potential energies of all the electron shells. 
D)  the potential energy of the valence shell.

Question 13

Van der Waals interactions may result when ________.

Accepted Answer

A)  electrons are not symmetrically distributed in a molecule 
B)  molecules held by ionic bonds react with water 
C)  two polar covalent bonds react 
D)  a hydrogen atom loses an electron 
A)  electrons are not symmetrically distributed in a molecule 
B)  molecules held by ionic bonds react with water 
C)  two polar covalent bonds react 
D)  a hydrogen atom loses an electron

Question 14

The atomic number of nitrogen is 7. Nitrogen-15 has a greater mass number than nitrogen-14 because the atomic nucleus of nitrogen-15 contains ________.

Accepted Answer

A)  7 neutrons 
B)  8 neutrons 
C)  8 protons 
D)  15 protons 
A)  7 neutrons 
B)  8 neutrons 
C)  8 protons 
D)  15 protons

Question 15

Refer to the following figure to answer the questions below.
  
-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 16

A(n)________ has charge but negligible mass, whereas a(n)________ has mass but no charge.

Accepted Answer

A)  proton; neutron 
B)  neutron; proton 
C)  neutron; electron 
D)  electron; neutron 
A)  proton; neutron 
B)  neutron; proton 
C)  neutron; electron 
D)  electron; neutron

Question 17

Refer to the following figure to answer the questions below.
3H₂ + N₂ $ \rightleftharpoons $ 2NH₃
-Which of the following correctly describes chemical equilibrium?

Accepted Answer

A)  Forward and reverse reactions continue with no net effect on the concentrations of the reactants and products. 
B)  Concentrations of products are higher than the concentrations of the reactants. 
C)  There are equal concentrations of products and reactants while forward and reverse reactions continue. 
D)  There are equal concentrations of reactants and products, and the reactions have stopped. 
A)  Forward and reverse reactions continue with no net effect on the concentrations of the reactants and products. 
B)  Concentrations of products are higher than the concentrations of the reactants. 
C)  There are equal concentrations of products and reactants while forward and reverse reactions continue. 
D)  There are equal concentrations of reactants and products, and the reactions have stopped.

Question 18

In a chemical reaction, the element ¹³Al will most preferably ________.

Accepted Answer

A)  lose three electrons and become positively charged 
B)  gain five electrons and become negatively charged 
C)  lose five electrons and become positively charged 
D)  gain three electrons and become positively charged 
A)  lose three electrons and become positively charged 
B)  gain five electrons and become negatively charged 
C)  lose five electrons and become positively charged 
D)  gain three electrons and become positively charged

Question 19

Which of the following statements is TRUE?

Accepted Answer

A)  Carbon, hydrogen, oxygen, and calcium are the most abundant elements of living matter. 
B)  Some naturally occurring elements are toxic to organisms. 
C)  All life requires the same essential elements. 
D)  A patient suffering from a goiter should not consume seafood. 
A)  Carbon, hydrogen, oxygen, and calcium are the most abundant elements of living matter. 
B)  Some naturally occurring elements are toxic to organisms. 
C)  All life requires the same essential elements. 
D)  A patient suffering from a goiter should not consume seafood.

Question 20

Which one of the atoms shown would be most likely to form an anion with a charge of -1?

Accepted Answer

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

Exam 2: The Chemical Context of Life

Can the atomic mass of an element vary?

What coefficients must be placed in the following blanks so that all atoms are accounted for in the products? C₆H₁₂O₆ → ________ C₂H₆O + ________ CO₂

Nitrogen (N)is more electronegative than hydrogen (H). Which of the following is a correct statement about the atoms in ammonia (NH₃)?

Atoms have no electric charge because they have ________.

A covalent chemical bond is one in which ________.

The atomic number of chlorine is 17. The atomic number of magnesium is 12. What is the formula for magnesium chloride?

Elements ⁷²Zn, ⁷⁵As, and ⁷⁴Ge have the ________.

In the term trace element, the adjective trace means that

In the following structure where A and B represent two different elements, the valency of A is ________ and B is ________.

Refer to the following figure (first three rows of the periodic table) to answer the questions below. -What element does not prefer to react with other elements?

Refer to the following figure to answer the questions below. -Based on electron configuration, which of the elements in the figure would exhibit a chemical behavior most like that of oxygen?

The reactivity of an atom arises from

Van der Waals interactions may result when ________.

The atomic number of nitrogen is 7. Nitrogen-15 has a greater mass number than nitrogen-14 because the atomic nucleus of nitrogen-15 contains ________.

Refer to the following figure to answer the questions below. -When the atoms involved in a covalent bond have the same electronegativity, what type of bond results?

A(n)________ has charge but negligible mass, whereas a(n)________ has mass but no charge.

Refer to the following figure to answer the questions below. 3H₂ + N₂ ⇌ \rightleftharpoons ⇌ 2NH₃ -Which of the following correctly describes chemical equilibrium?

In a chemical reaction, the element ¹³Al will most preferably ________.

Which of the following statements is TRUE?

Which one of the atoms shown would be most likely to form an anion with a charge of -1?

Evolution, the Themes of Biology, and Scientific Inquiry

Water and Life

Carbon and the Molecular Diversity of Life

The Structure and Function of Large Biological Molecules

A Tour of the Cell

Membrane Structure and Function

An Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cell Communication

The Cell Cycle

Meiosis and Sexual Life Cycles

Mendel and the Gene Idea

The Chromosomal Basis of Inheritance

The Molecular Basis of Inheritance

Gene Expression: From Gene to Protein

Regulation of Gene Expression

Viruses

DNA Tools and Biotechnology

Genomes and Their Evolution

Descent with Modification: A Darwinian View of Life

The Evolution of Populations

The Origin of Species

The History of Life on Earth

Phylogeny and the Tree of Life

Bacteria and Archaea

Protists

Plant Diversity I: How Plants Colonized Land

Plant Diversity II: The Evolution of Seed Plants

Fungi

An Overview of Animal Diversity

An Introduction to Invertebrates

The Origin and Evolution of Vertebrates

Vascular Plant Structure, Growth, and Development

Resource Acquisition and Transport in Vascular Plants

Soil and Plant Nutrition

Angiosperm Reproduction and Biotechnology

Plant Responses to Internal and External Signals

Basic Principles of Animal Form and Function

Animal Nutrition

Circulation and Gas Exchange

The Immune System

Osmoregulation and Excretion

Hormones and the Endocrine System

Animal Reproduction

Animal Development

Neurons, Synapses, and Signaling

Nervous Systems

Sensory and Motor Mechanisms

Animal Behavior

An Introduction to Ecology and the Biosphere

Population Ecology

Community Ecology

Ecosystems and Restoration Ecology

Conservation Biology and Global Change

Filters

What coefficients must be placed in the following blanks so that all atoms are accounted for in the products? C₆H₁₂O₆ → C₂H₆O + CO₂

In the following structure where A and B represent two different elements, the valency of A is and B is .

A(n) has charge but negligible mass, whereas a(n) has mass but no charge.

Refer to the following figure to answer the questions below. 3H₂ + N₂ $\rightleftharpoons$ 2NH₃ -Which of the following correctly describes chemical equilibrium?