Question 1

The atomic number of hydrogen is 1. Based on this fact, all of the following must be true of hydrogen gas (H2) EXCEPT that it

Accepted Answer

A)  uses covalent bonds to form the molecule. 
B)  is a polar molecule. 
C)  is a stable molecule. 
D)  shares one pair of electrons between the two hydrogen atoms. 
A)  uses covalent bonds to form the molecule. 
B)  is a polar molecule. 
C)  is a stable molecule. 
D)  shares one pair of electrons between the two hydrogen atoms.

Question 2

Which of the following properties of water enable(s) it to function as a regulator of temperature for living organisms? (Hint: Think about what happens when you are sunbathing.)

Accepted Answer

A)  High specific heat 
B)  High specific heat and high heat of vaporization 
C)  High heat of vaporization 
D)  High specific heat and low heat of vaporization 
E)  Low specific heat 
A)  High specific heat 
B)  High specific heat and high heat of vaporization 
C)  High heat of vaporization 
D)  High specific heat and low heat of vaporization 
E)  Low specific heat

Question 3

In general, a substance that carries an electric charge can dissolve in water. Given this fact, which of the following would most likely NOT dissolve in water?

Accepted Answer

A)  NaCl 
B)  Polar covalent molecules 
C)  Nonpolar molecules 
D)  Ionic compounds 
A)  NaCl 
B)  Polar covalent molecules 
C)  Nonpolar molecules 
D)  Ionic compounds

Question 4

The human body must maintain a constant pH. In the blood, bicarbonate serves as a(n)_________ to help maintain the necessary pH.

Accepted Answer

A)  buffer 
B)  acid 
C)  base 
D)  solvent 
A)  buffer 
B)  acid 
C)  base 
D)  solvent

Question 5

Most biological molecules are joined by

Accepted Answer

A)  peptide bonds. 
B)  ionic bonds. 
C)  covalent bonds. 
D)  hydrogen bonds. 
E)  disulfide bonds. 
A)  peptide bonds. 
B)  ionic bonds. 
C)  covalent bonds. 
D)  hydrogen bonds. 
E)  disulfide bonds.

Question 6

Free radicals contain unpaired electrons in their outermost energy shell, so they react readily with other atoms or molecules to reach a more stable state. Which of the following could potentially be a free radical?

Accepted Answer

A)  Fluorine (atomic number 9) 
B)  Neon (atomic number 10) 
C)  Magnesium (atomic number 12) 
D)  Helium (atomic number 2) 
A)  Fluorine (atomic number 9) 
B)  Neon (atomic number 10) 
C)  Magnesium (atomic number 12) 
D)  Helium (atomic number 2)

Question 7

Water molecules are cohesive because they

Accepted Answer

A)  make up 60% to 90% of an organismʹs body weight. 
B)  stick to other polar molecules. 
C)  form hydrogen bonds. 
D)  contain protons. 
E)  are repelled by nonpolar molecules. 
A)  make up 60% to 90% of an organismʹs body weight. 
B)  stick to other polar molecules. 
C)  form hydrogen bonds. 
D)  contain protons. 
E)  are repelled by nonpolar molecules.

Question 8

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

Question 9

If sulfur has an atomic number of 16, how many covalent bonds can it form with other atoms?

Accepted Answer

A)  Four 
B)  Two 
C)  Zero 
D)  Eight 
E)  Six 
A)  Four 
B)  Two 
C)  Zero 
D)  Eight 
E)  Six

Question 10

Which of the following best explains the attraction of water molecules to each other?

Accepted Answer

A)  Nonpolar covalent bond 
B)  Polar covalent bond 
C)  Ionic bond 
D)  Hydrogen bond 
E)  Electron-proton interaction 
A)  Nonpolar covalent bond 
B)  Polar covalent bond 
C)  Ionic bond 
D)  Hydrogen bond 
E)  Electron-proton interaction

Question 11

A neutral solution

Accepted Answer

A)  has no H+. 
B)  has no OH-. 
C)  is hydrophobic. 
D)  has a pH of 0. 
E)  has equal amounts of H+ and OH-. 
A)  has no H+. 
B)  has no OH-. 
C)  is hydrophobic. 
D)  has a pH of 0. 
E)  has equal amounts of H+ and OH-.

Question 12

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

Accepted Answer

A) True 
 B)False

Question 13

The formation of sodium chloride (NaCl) is the result of

Accepted Answer

A)  attraction between opposite charges. 
B)  repelling between the same charges. 
C)  chemical unreactivity. 
D)  covalent bonding. 
A)  attraction between opposite charges. 
B)  repelling between the same charges. 
C)  chemical unreactivity. 
D)  covalent bonding.

Question 14

What is the difference between covalent and ionic bonds?)

Accepted Answer

Covalent bonds are the sharing

Question 15

Which of the following is LEAST affected by the presence of water?

Accepted Answer

A)  Nonpolar covalent bond 
B)  Polar covalent bond 
C)  Ionic bond 
D)  Hydrogen bond 
E)  Electron-proton interaction 
A)  Nonpolar covalent bond 
B)  Polar covalent bond 
C)  Ionic bond 
D)  Hydrogen bond 
E)  Electron-proton interaction

Question 16

Which of the following pairs has the most similar chemical properties to each other?

Accepted Answer

A)  1H and 2He 
B)  12C and 14C 
C)  12C and 28Si 
D)  1H and 22Na 
E)  16O and 32S 
A)  1H and 2He 
B)  12C and 14C 
C)  12C and 28Si 
D)  1H and 22Na 
E)  16O and 32S

Question 17

The hydrogen bond between two water molecules forms because water is

Accepted Answer

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

Question 18

Carbon-14 is often used for carbon dating, where scientists measure the rate of carbon-14 decay to determine the age of items. Carbon-14 contains six protons and eight neutrons. During the process of carbon-14 decay, one of its eight neutrons becomes a proton and an electron is emitted. Which of the following is the best explanation of what has occurred?

Accepted Answer

A)  The resulting atom has a more stable nucleus. 
B)  The resulting atom is still carbon-14. 
C)  An ionic bond has formed. 
D)  The resulting atom is now a different element because the number of protons has changed. 
A)  The resulting atom has a more stable nucleus. 
B)  The resulting atom is still carbon-14. 
C)  An ionic bond has formed. 
D)  The resulting atom is now a different element because the number of protons has changed.

Question 19

The specific heat of water is 10 times greater than that of iron. You place a metal pot full of water on the stove to heat it up. You touch the metal handle of the pot when the water is still only lukewarm. Which of the following best describes what happens?

Accepted Answer

A)  You find that the handle is cooler than the water in the pot. 
B)  You determine that metal pots full of water produce acids and bases. 
C)  You find that both the water and the handle are the same temperature. 
D)  You burn your finger and pull your hand away from the hot metal handle. 
A)  You find that the handle is cooler than the water in the pot. 
B)  You determine that metal pots full of water produce acids and bases. 
C)  You find that both the water and the handle are the same temperature. 
D)  You burn your finger and pull your hand away from the hot metal handle.

Question 20

Which statement is an accurate description of water molecules?

Accepted Answer

A)  They are ionically bonded. 
B)  They are uncharged and nonpolar. 
C)  They are slightly charged and polar. 
D)  They are charged and nonpolar. 
A)  They are ionically bonded. 
B)  They are uncharged and nonpolar. 
C)  They are slightly charged and polar. 
D)  They are charged and nonpolar.

Exam 2: Atoms, Molecules, and Life

The atomic number of hydrogen is 1. Based on this fact, all of the following must be true of hydrogen gas (H2) EXCEPT that it

Which of the following properties of water enable(s) it to function as a regulator of temperature for living organisms? (Hint: Think about what happens when you are sunbathing.)

In general, a substance that carries an electric charge can dissolve in water. Given this fact, which of the following would most likely NOT dissolve in water?

The human body must maintain a constant pH. In the blood, bicarbonate serves as a(n)_________ to help maintain the necessary pH.

Most biological molecules are joined by

Free radicals contain unpaired electrons in their outermost energy shell, so they react readily with other atoms or molecules to reach a more stable state. Which of the following could potentially be a free radical?

Water molecules are cohesive because they

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?

If sulfur has an atomic number of 16, how many covalent bonds can it form with other atoms?

Which of the following best explains the attraction of water molecules to each other?

A neutral solution

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

The formation of sodium chloride (NaCl) is the result of

What is the difference between covalent and ionic bonds?)

Which of the following is LEAST affected by the presence of water?

Which of the following pairs has the most similar chemical properties to each other?

The hydrogen bond between two water molecules forms because water is

The specific heat of water is 10 times greater than that of iron. You place a metal pot full of water on the stove to heat it up. You touch the metal handle of the pot when the water is still only lukewarm. Which of the following best describes what happens?

Which statement is an accurate description of water molecules?

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?