Deck 2: Life, Chemistry, and Water

Question 1

Hydrogen, atomic number 1, has 3 isotopes, ¹H, ²H, ³H. ¹H is comprised of one proton, one neutron and one electron.

Answer 1

False

Question 2

Radioactive ____ is commonly used to treat patients with dangerously overactive thyroid glands. ​

A)carbon
B)radium
C)iodine
D)thallium
E)cobalt

Answer 2

C

Question 3

Figure 2.1
Answer the question using the accompanying figure. The mass number of the atom depicted in the figure is ____. ​

A)​4
B)​6
C)​8
D)​12
E)​18

Answer 3

D

Question 4

Diluted acetic acid, CH₃COOH, is commonly called vinegar. How many atoms of hydrogen are present in one molecule of acetic acid? ​

A)one
B)two
C)three
D)four
E)five

Question 5

Atoms with atomic numbers between lithium and neon have two energy levels.

Question 6

Four elements, including ____, make up more than 96% of the mass of most living organisms.

A)sodium
B)potassium
C)phosphorus
D)nitrogen
E)calcium

Question 7

Proteins in thermophiles must be stabilized by van der Waals forces, because hydrogen bonds cannot be maintained at high temperatures

Question 8

Acid precipitation can have a pH as low as 3.

Question 9

A trace element is one found in specific organisms in ____ quantities and is ____ for normal biological functions.

A)moderate; unnecessary
B)moderate; vital
C)small; unnecessary
D)large; unnecessary
E)small; vital ​

Question 10

The substance O₂ is considered to be ____. ​

A)both a molecule and a compound
B)a compound but not a molecule
C)neither a molecule nor a compound
D)a molecule but not a compound
E)both a molecule and an ion

Question 11

An oxygen atom has ____ surrounding a nucleus composed of ____. ​

A)neutrons; electrons and protons
B)electrons; protons and neutrons
C)protons and electrons; neutrons
D)protons; neutrons and electrons
E)electrons and neutrons; protons

Question 12

The four elements that make up more than 96% of the weight of living organisms are oxygen, carbon, hydrogen and calcium.

Question 13

The substance H₂O is considered to be ____. ​

A)both a molecule and a compound
B)a compound but not a molecule
C)neither a molecule nor a compound
D)a molecule but not a compound
E)both a molecule and an ion

Question 14

In the representation of hydrogen gas, H-H, the dash represents two electrons being shared equally.

Question 15

The polarity of water allows it to create a hydration layer that prevents salt from coming back out of solution after it has been dissolved.

Question 16

The smallest unit that retains the chemical and physical properties of an element is a(n)____. ​

A)proton
B)compound
C)molecule
D)neutron
E)atom

Question 17

Ice floats in liquid water because there are, on average, fewer hydrogen bonds between molecules in ice than water, resulting in a lower density. ​

Question 18

Buffers can increase the pH of a solution when acids are added.

Question 19

Carbon dioxide is an element.

Question 20

Prolonged iodine deficiency causes ____, a condition in which the thyroid gland enlarges so much that the front of the neck swells significantly. ​

A)gout
B)cancer
C)a goiter
D)anemia
E)granuloma

Question 21

The attraction between Na⁺ cations and Cl^- anions form ____ that hold the ions together in the compound NaCl. ​

A)polar covalent bonds
B)van der Waals forces
C)ionic bonds
D)hydrogen bonds
E)nonpolar covalent bonds

Question 22

Figure 2.1
Answer the question using the accompanying figure. The atom depicted in this figure can form ____ covalent bonds with another atom. ​

A)​0
B)​2
C)​4
D)​3
E)​6

Question 23

An orbital describes the ____ of an electron. ​

A)exact location
B)exact path
C)most frequent locations
D)charge
E)chemical bonds

Question 24

The chemical linkages that exert an attractive force over the greatest distance are ____.

A)polar covalent bonds
B)van der Waals forces
C)ionic bonds
D)hydrogen bonds
E)nonpolar covalent bonds

Question 25

Which element is likely to be chemically unreactive? ​

A)chlorine (7 valence electrons)
B)calcium (2 valence electrons)
C)argon (8 valence electrons)
D)carbon (4 valence electrons)
E)potassium (1 valence electron)

Question 26

Chemical bonds that are formed when one atom with a partial positive charge (created from unequal sharing of electrons)is electrically attracted to another atom with a partial negative charge (also created from unequal sharing of electrons)are called ____. ​

A)polar covalent bonds
B)van der Waals forces
C)ionic bonds
D)hydrogen bonds
E)nonpolar covalent bonds

Question 27

When the isotope ¹⁴C undergoes radioactive decay, a neutron splits into an electron and a proton, with ejection of the electron. This decay produces an atom of ____. ​

A)iron
B)carbon
C)hydrogen
D)oxygen
E)nitrogen

Question 28

Figure 2.1
Answer the question using the accompanying figure. The atomic number of the atom depicted in the figure is ____. ​

A)​4
B)​6
C)​8
D)​12
E)​18

Question 29

 
Figure 2.2
Answer the question using the accompanying figure. The electrons at the lowest energy level in the neon atom depicted are found in which orbital? ​

A)1 s
B)2 s
C)2 p x
D)2 p y
E)2 p z

Question 30

¹⁴ C is heavier than ¹²C because it has ____. ​

A)two more electrons than ¹²C
B)two more neutrons than ¹²C
C)two more protons than ¹²C
D)two more protons and two more electrons than ¹²C
E)one more proton and one more neutron than ¹²C

Question 31

 
Figure 2.2
Answer the question using the accompanying figure. All of the orbitals shown in the neon atom are completely filled with electrons. How many electrons does this neon atom have?

A)​5
B)​6
C)​8
D)​10
E)​16

Question 32

Which element is most likely to accept an electron from another atom? ​

A)chlorine (7 valence electrons)
B)calcium (2 valence electrons)
C)neon (8 valence electrons)
D)carbon (4 valence electrons)
E)potassium (1 valence electron)

Question 33

A carbon atom with six protons, seven neutrons, and six electrons has a mass number of ____. ​

A)​6
B)​7
C)​12
D)​13
E)​19

Question 34

The chemical bonds that are formed when atoms share electrons equally are called ____.

A)polar covalent bonds
B)van der Waals forces
C)ionic bonds
D)hydrogen bonds
E)nonpolar covalent bonds

Question 35

Which element is most likely to share electrons with other atoms in joint orbitals? ​

A)chlorine (7 valence electrons)
B)calcium (2 valence electrons)
C)argon (8 valence electrons)
D)carbon (4 valence electrons)
E)potassium (1 valence electron)

Question 36

Sodium has one valence electron in its third energy level. To reach a stable energy configuration, sodium will tend to____. ​

A)take up an electron from another atom
B)move its valence electron to the second energy shell
C)give up an electron to another atom
D)share its valence electron with another atom
E)move an electron from the second energy level to the valence shell

Question 37

Electronegativity is the tendency of an atom to attract ____ to itself in a chemical bond. ​

A)neutrons
B)protons
C)electrons
D)delta forces
E)polar associations

Question 38

Which of the three atomic particles are charged? ​

A)electrons and protons
B)neutrons only
C)protons and neutrons
D)electrons only
E)protons, neutrons, and electrons

Question 39

Metallic ions such as Ca²⁺, Na⁺, and Fe³⁺ readily form ____. ​

A)polar covalent bonds
B)van der Waals forces
C)ionic bonds
D)hydrogen bonds
E)nonpolar covalent bonds

Question 40

Isotopes of the same element differ from each other in the number of ____. ​

A)electrons and protons
B)neutrons only
C)protons and neutrons
D)electrons only
E)protons, neutrons, and electrons

Question 41

The hydrogen-bond lattice causes water to have an unusually ____ specific heat, an unusually ____ heat of vaporization and an unusually ____ density in solid form. ​

A)high; high; high
B)low; low; low
C)high; low; high
D)high; high; low
E)low; low; high

Question 42

The formation and breaking of bonds between atoms requires ____. ​

A)a chemical reaction
B)van der Walls forces
C)partial charges
D)an empty valence shell
E)an enzyme

Question 43

Geckos are able to cling to vertical walls due to ____. ​

A)polar covalent bonds
B)van der Waals forces
C)ionic bonds
D)hydrogen bonds
E)nonpolar covalent bonds

Question 44

A polar covalent bond would be most likely to form between ____. ​

A)atoms with different electronegativities
B)cations and anions
C)atoms with partial positive and partial negative charges
D)atoms with filled valence shells
E)atoms of the same element

Question 45

A mixture of vegetable oil and water will separate into layers because oil is ____ and forms ____.

A)hydrophobic; nonpolar associations
B)hydrophilic; nonpolar associations
C)hydrophilic; polar associations
D)hydrophobic; polar associations
E)hydrophobic; ionic associations

Question 46

In contrast to ionic bonds, covalent bonds ____. ​

A)hold atoms together
B)have distinct, three-dimensional forms
C)transfer electrons from one atom to another
D)are rarely broken
E)are transient

Question 47

Figure 2.4
The water strider shown in the figure above is able to stand on water because of the ____ of water.

A)covalent bonds
B)surface tension
C)van der Waals forces
D)density
E)hydration layer

Question 48

In a molecule of methane, CH₄, each hydrogen atom shares an orbital with the carbon atom. The total number of shared electrons in CH₄ is ____. ​

A)​1
B)​2
C)​4
D)​5
E)​8

Question 49

Multiple hydrogen bonds together stabilize proteins into a spiral structure called a ____.

A)water lattice
B)alpha helix
C)chemical groups
D)delta minus
E)delta plus

Question 50

How many calories, as defined in chemistry, are in one calorie, which is the unit used to quantify the amount of energy in the food we eat? ​

A)​10
B)​100
C)​1,000
D)​10,000
E)​100,000

Question 51

In the presence of water, nonpolar associations form between molecules or regions of molecules that are ____. ​

A)partially charged
B)hydrophobic and hydrophilic
C)hydrophobic
D)fully charged
E)hydrophilic

Question 52

Which substance would have the most difficulty entering a water lattice? ​

A)table salt (NaCl)
B)a nonpolar molecule
C)a sodium ion
D)a proton (H⁺)
E)an electron

Question 53

Which type of chemical linkage is the weakest? ​

A)polar covalent bonds
B)van der Waals forces
C)ionic bonds
D)hydrogen bonds
E)nonpolar covalent bonds

Question 54

 
Figure 2.3
Answer the question using the accompanying figure. The molecule shown is held together by ____. ​

A)polar covalent bonds
B)van der Waals forces
C)ionic bonds
D)hydrogen bonds
E)nonpolar covalent bonds

Question 55

A molecule of water in the middle of a chunk of ice will usually have ____ hydrogen bonds with other water molecules. ​

A)​2
B)​3
C)​3.4
D)​4
E)6​

Question 56

Water has an important stabilizing effect on temperature in living organisms and their environments because as water absorbs heat, much of the energy is used to ____ instead of raising the temperature. ​

A)create hydrogen bonds
B)create covalent bonds
C)break surface tension
D)break hydrogen bonds
E)create hydration layers

Question 57

Molecules such as H-H and O=O are held together by ____. ​

A)polar covalent bonds
B)van der Waals forces
C)ionic bonds
D)hydrogen bonds
E)nonpolar covalent bonds

Question 58

Water has an unusually high boiling point for its molecular weight because water molecules ____. ​

A)are very dense
B)get much heavier as they are heated
C)are held to each other by hydrogen bonds
D)are held together by covalent bonds
E)form hydration layers

Question 59

When water molecules exposed to the air form hydrogen bonds between adjacent water molecules below and beside them, molecules in the upper layer become more resistant to separating from those underneath.  This property of water is known as ____. ​

A)cohesion
B)adhesion
C)a hydration layer
D)a water lattice
E)surface tension

Question 60

Figure 2.5
The water lattice illustrated in the figure above forms as a result of ____ between water molecules. ​

A)covalent bonds
B)hydrogen bonds
C)nonpolar interactions
D)ionic bonds
E)van der Walls forces

Question 61

Lemon juice has a pH of 2.0, therefore, ____. ​

A)[H⁺]
B)[H⁺] = [OH^-]
C)[H⁺] = 0
D)[OH^-] = 0
E)[H⁺] > [OH^-]

Question 62

Biological membranes are held together mainly by ____. ​

A)hydrogen bonds between lipid molecules
B)hydration layers over lipid molecules
C)exclusion of the nonpolar regions of lipids by water
D)hydrogen bonds between water molecules
E)surface tension at the interface between layers of water molecules

Question 63

High levels of carbon dioxide in the atmosphere are causing ____. ​

A)the pH of the ocean to increase
B)the pH of the ocean to decrease
C)the natural buffers in the ocean to die
D)increased calcification of the coral reefs
E)increased biodiversity in coral reefs

Question 64

When sugar dissolves in water, water is acting as a ____ and the sugar molecules are acting as ____. ​

A)solution; solvents
B)solute; solutions
C)solvent; solutes
D)solute; solvents
E)solvent; solutions

Question 65

In water, NaOH almost completely separates into Na⁺ and OH^- ions. Thus, NaOH is _____. ​

A)a strong acid
B)a strong base
C)a weak acid
D)a weak base
E)neutral

Question 66

Water has a molecular weight of 18 g per mole, and glucose has a molecular weight of 180 g per mole. Which masses of water and glucose would have an approximately equal number of molecules? ​

A)1 g of water and 180 g of glucose
B)90 g of water and 9 g of glucose
C)180 g of water and 1 g of glucose
D)9 g of water and 90 g of glucose
E)90 g of water and 90 g of glucose

Question 67

When salt dissolves in water, the water molecules form ____ around the Na⁺ and Cl^- ions. ​

A)covalent bonds
B)hydration layers
C)nonpolar interactions
D)membranes
E)ionic bonds

Question 68

When added to water at neutral pH (7.0), an acid will ____. ​

A)act as a proton donor, raising the pH of the solution
B)act as a proton acceptor, raising the pH of the solution
C)act as a proton donor, lowering the pH of the solution
D)act as a proton acceptor, lowering the pH of the solution
E)do nothing since the aqueous solution is neutral

Question 69

Ethanol, the alcohol found in wine and beer, has the molecular formula CH₃CH₂OH. What is the molecular weight of ethanol if the atomic weight of C=12, H=1 and O=16? ​

A)29 g/mol
B)30 g/mol
C)34 g/mol
D)45 g/mol
E)46 g/mol

Question 70

Avogadro's number represents the ____. ​

A)number of grams in a mole of substance
B)number of moles in a gram of substance
C)number of atoms in one gram of substance
D)atomic weight of an atom divided by the weight of an atom of that element
E)weight of an atom of an element divided by the atomic weight of that element

Question 71

A pH of 6 is ____ times more ____ than a pH of 2. ​

A)3; acidic
B)4; acidic
C)3; basic
D)10,000; basic
E)40; basic

Question 72

Seawater typically is ____. ​

A)highly basic
B)neutral
C)somewhat basic
D)somewhat acidic
E)highly basic

Question 73

The most common isotope of carbon has an atomic number of 6 and a mass number of 12, while the most common isotope of oxygen has an atomic number of 8 and a mass number of 16. A molecule of CO₂ made up of these common isotopes has a molecular weight of ____. ​

A)​28
B)​44
C)​56
D)​14
E)22​

Question 74

Consider the equilibrium established in the carbonic acid-bicarbonate buffer system, which maintains pH balance in mammalian blood:
          H₂CO₃ → HCO ₃ ^- + H ⁺
During hypoventilation, breathing rate decreases, and therefore elimination of CO ₂ during exhalation decreases. How is optimal blood pH maintained when acid levels increase in our blood from hypoventilating? ​

A)excess H ⁺ from the acid react with H₂CO₃ to decrease pH level
B)excess H ⁺ from the acid react with H₂CO₃ to increase pH level
C)excess H ⁺ from the acid react with H₂CO₃ to maintain pH level
D)excess H ⁺ from the acid react with HCO ₃ ^- to increase pH level
E)excess H ⁺ from the acid react with HCO ₃ ^- to maintain pH level

Question 75

Most pH buffers are ____. ​

A)strong acids
B)weak acids or weak bases
C)weak acids
D)strong bases
E)strong acids or strong bases

Question 76

Without ____, living organisms would often experience major changes in pH in their cells. ​

A)buffers
B)acids
C)surface tension
D)nonpolar bonds
E)bases

Question 77

Solution A has a pH of 6 and solution B has a pH of 8. Therefore, ____. ​

A)A has 10 times greater H⁺ concentration than B.
B)B has 10 times greater H⁺ concentration than A.
C)A has 100 times greater H⁺ concentration than B.
D)B has 100 times greater H⁺ concentration than A.
E)A has 1,000 times greater H⁺ concentration than B.

Question 78

Pure water has a pH of 7.0, therefore, ____. ​

A)[H⁺]
B)[H⁺] = [OH^-]
C)[H⁺] = 0
D)[OH^-] = 0
E)[H⁺] > [OH^-]

Question 79

When added to water, a base will act as a(n)____ and cause the pH of the solution to ____. ​

A)proton acceptor; rise
B)proton donor; rise
C)proton acceptor; fall
D)proton donor; fall
E)acid; fall

Question 80

A ____ is formed when a ____ is dissolved in a ____. ​

A)solution; solute; solvent
B)solute; solvent; solution
C)solution; solvent; solute
D)solvent; solution; solute
E)solvent; solute; solution