Question 1

If you place a feather on the surface of a bowl of water, the feather remains suspended on the surface due to the

Accepted Answer

A)  polarity of the water. 
B)  fact that water is a good solvent. 
C)  density of the water. 
D)  surface tension of the water. 
A)  polarity of the water. 
B)  fact that water is a good solvent. 
C)  density of the water. 
D)  surface tension of the water. D

Question 2

All animals need oxygen gas (O2) for their primary cellular- level functioning. Inside the cell, O2 is split apart into oxygen atoms. Eventually, electrons that are flowing through the cell will be "received" by this oxygen. But f electrons combine with protons present in the cell to form a basic element that has a single proton and a single el Then this element combines with the oxygen to form a certain chemical compound. In this scenario, what chemical compound is produced when this element combines with oxygen?

Accepted Answer

A)  Water (H2O) 
B)  Bicarbonate (HCO3) 
C)  Ozone (O3) 
D)  Carbon dioxide (CO2) 
A)  Water (H2O) 
B)  Bicarbonate (HCO3) 
C)  Ozone (O3) 
D)  Carbon dioxide (CO2) A

Question 3

The fact that salt dissolves in water is best explained by the

Accepted Answer

A)  hydrophobic nature of salt. 
B)  ionic nature of water molecules. 
C)  slightly charged nature of water molecules. 
D)  polar nature of water molecules. 
E)  hydrophobic nature of the water. 
A)  hydrophobic nature of salt. 
B)  ionic nature of water molecules. 
C)  slightly charged nature of water molecules. 
D)  polar nature of water molecules. 
E)  hydrophobic nature of the water. D

Question 4

An atom of nitrogen attracts electrons more strongly than an atom of hydrogen. In an ammonia molecule (NH3), which of the following best describes the electrical charge of the individual atoms?

Accepted Answer

A)  The nitrogen becomes neutral. 
B)  The nitrogen is slightly more negative. 
C)  The hydrogens are strongly negative. 
D)  The nitrogen is slightly positive. 
E)  Charges balance out and none of the atoms has any charge. 
A)  The nitrogen becomes neutral. 
B)  The nitrogen is slightly more negative. 
C)  The hydrogens are strongly negative. 
D)  The nitrogen is slightly positive. 
E)  Charges balance out and none of the atoms has any charge.

Question 5

Which of the following represents a molecule characterized by polar covalent bonding?

Accepted Answer

A)  O2 
B)  H2O 
C)  H2 
D)  NaCl 
E)  CH4 
A)  O2 
B)  H2O 
C)  H2 
D)  NaCl 
E)  CH4

Question 6

Isotopes are atoms of the same element that have different numbers of protons.

Accepted Answer

A) True 
 B)False

Question 7

What determines the cohesiveness of water molecules?

Accepted Answer

A)  Ionic bonds 
B)  Hydrophobic interactions 
C)  Covalent bonds 
D)  Hydrogen bonds 
A)  Ionic bonds 
B)  Hydrophobic interactions 
C)  Covalent bonds 
D)  Hydrogen bonds

Question 8

What is meant by the statement that water has a high specific heat?

Accepted Answer

A)  Water freezes easily. 
B)  The boiling point of water is low. 
C)  It can absorb a lot of energy without changing temperature. 
D)  It grows hot quickly. 
E)  Water can heat up to only a certain temperature. 
A)  Water freezes easily. 
B)  The boiling point of water is low. 
C)  It can absorb a lot of energy without changing temperature. 
D)  It grows hot quickly. 
E)  Water can heat up to only a certain temperature.

Question 9

Imagine that you are trying to make a homemade salad dressing and place several drops of olive oil into a container of water. You stir the solution, but the oil doesn't readily mix. Instead, you observe a glistening clump of oil floating on the surface. Explain what is happening at the molecular level. (Your answer should include the term hydrophobic.)

Accepted Answer

When oil molecules are together in water

Question 10

To maintain a constant pH, buffers act to either accept or release H+.

Accepted Answer

A) True 
 B)False

Question 11

Iron is an important element in human body cells. If iron has an atomic number of 26, what does this tell you about this element?

Accepted Answer

A)  An iron atom has 13 protons and 13 neutrons. 
B)  An iron atom has 13 electrons and 13 protons. 
C)  An iron atom has 26 protons. 
D)  An iron atom is unable to become an isotope. 
A)  An iron atom has 13 protons and 13 neutrons. 
B)  An iron atom has 13 electrons and 13 protons. 
C)  An iron atom has 26 protons. 
D)  An iron atom is unable to become an isotope.

Question 12

Different types of living matter often have different forms of the same elements in their bodies. For example, the nitrogen in an animal often has a slightly different atomic structure than the nitrogen in a plant. Recently, nutriti have discovered how to deduce the diets of various animal species by examining the type of nitrogen (and other elements) inside their bodies. What is the chemical basis behind this scenario?

Accepted Answer

A)  Covalent bonds result when two atoms share electrons. 
B)  Isotopes of the same element have the same atomic number but different atomic masses. 
C)  Hydrophobic interactions keep water molecules from forming bonds with fats and oils. 
D)  Antioxidants buffer the potential damage that free radicals do to cells. 
E)  Radioactive elements can be used to trace the paths of molecules through the body. 
A)  Covalent bonds result when two atoms share electrons. 
B)  Isotopes of the same element have the same atomic number but different atomic masses. 
C)  Hydrophobic interactions keep water molecules from forming bonds with fats and oils. 
D)  Antioxidants buffer the potential damage that free radicals do to cells. 
E)  Radioactive elements can be used to trace the paths of molecules through the body.

Question 13

A basilisk lizard can run across the surface of a pond due to a property of water called .

Accepted Answer

The answer of A basilisk lizard can run across the...

Question 14

What property of water, in which water molecules stick to each other, is responsible for the ability of plants to get water from their roots up to their leaves?

Accepted Answer

The answer of What property of water, in which water...

Question 15

Isotopes are atoms of the same element that have different numbers of _ .

Accepted Answer

The answer of Isotopes are atoms of the same element...

Question 16

What happens when hydrochloric acid (HCl) dissociates in pure water?

Accepted Answer

A)  The HCl molecules separate into H+ and Cl- ions. 
B)  The concentration of OH- ions increases. 
C)  The HCl molecules float on top of the water. 
D)  The pH of the solution increases. 
E)  The water has a decrease of H+ ions. 
A)  The HCl molecules separate into H+ and Cl- ions. 
B)  The concentration of OH- ions increases. 
C)  The HCl molecules float on top of the water. 
D)  The pH of the solution increases. 
E)  The water has a decrease of H+ ions.

Question 17

Which of the following is attracted to the hydrogen "end" of a water molecule, as depicted in this figure?

Accepted Answer

A)  NaCl 
B)  Na+ 
C)  H 
D)  Cl- 
A)  NaCl 
B)  Na+ 
C)  H 
D)  Cl-

Question 18

Polar covalent bonds form when

Accepted Answer

A)  more than one pair of electrons is shared. 
B)  electrons are shared unequally between atoms. 
C)  atoms from two molecules are repelling each other. 
D)  an acid and a base are combined. 
E)  ions are formed. 
A)  more than one pair of electrons is shared. 
B)  electrons are shared unequally between atoms. 
C)  atoms from two molecules are repelling each other. 
D)  an acid and a base are combined. 
E)  ions are formed.

Question 19

The hydrogen bond between two water molecules forms because water is

Accepted Answer

A)  polar. 
B)  hydrophobic. 
C)  nonpolar. 
D)  a large molecule. 
E)  a small molecule. 
A)  polar. 
B)  hydrophobic. 
C)  nonpolar. 
D)  a large molecule. 
E)  a small molecule.

Question 20

The attractive force that holds two or more water molecules together is an example of an ionic bond.

Accepted Answer

A) True 
 B)False

Exam 2: Atoms, Molecules, and Life

If you place a feather on the surface of a bowl of water, the feather remains suspended on the surface due to the

The fact that salt dissolves in water is best explained by the

An atom of nitrogen attracts electrons more strongly than an atom of hydrogen. In an ammonia molecule (NH3), which of the following best describes the electrical charge of the individual atoms?

Which of the following represents a molecule characterized by polar covalent bonding?

Isotopes are atoms of the same element that have different numbers of protons.

What determines the cohesiveness of water molecules?

What is meant by the statement that water has a high specific heat?

To maintain a constant pH, buffers act to either accept or release H+.

Iron is an important element in human body cells. If iron has an atomic number of 26, what does this tell you about this element?

A basilisk lizard can run across the surface of a pond due to a property of water called .

What property of water, in which water molecules stick to each other, is responsible for the ability of plants to get water from their roots up to their leaves?

Isotopes are atoms of the same element that have different numbers of _ .

What happens when hydrochloric acid (HCl) dissociates in pure water?

Which of the following is attracted to the hydrogen "end" of a water molecule, as depicted in this figure?

Polar covalent bonds form when

The hydrogen bond between two water molecules forms because water is

The attractive force that holds two or more water molecules together is an example of an ionic bond.

An Introduction to Life on Earth

Biological Molecules

Cell Structure and Function

Cell Membrane Structure and Function

Energy Flow in the Life of a Cell

Capturing Solar Energy: Photosynthesis

Harvesting Energy: Glycolysis and Cellular Respiration

Cellular Reproduction

Meiosis: the Basis of Sexual Reproduction

Patterns of Inheritance

Dna: the Molecule of Heredity

Gene Expression and Regulation

Biotechnology

Principles of Evolution

How Populations Evolve

The Origin of Species

The History of Life

Systematics: Seeking Order Amid Diversity

The Diversity of Prokaryotes and Viruses

The Diversity of Protists

The Diversity of Plants

The Diversity of Fungi

Animal Diversity I: Invertebrates

Animal Diversity II: Vertebrates

Animal Behavior

Population Growth and Regulation

Community Interactions

Energy Flow and Nutrient Cycling in Ecosystems

Earths Diverse Ecosystems

Conserving Earths Biodiversity

Homeostasis and the Organization of the Animal Body

Circulation

Respiration

Nutrition and Digestion

The Urinary System

Defenses Against Disease

Chemical Control of the Animal Body: the Endocrine System

The Nervous System

The Senses

Action and Support: the Muscles and Skeleton

Animal Reproduction

Animal Development

Plant Anatomy and Nutrient Transport

Plant Reproduction and Development

Plant Responses to the Environment

Filters

An atom of nitrogen attracts electrons more strongly than an atom of hydrogen. In an ammonia molecule (NH₃), which of the following best describes the electrical charge of the individual atoms?