Deck 2: Life's Chemical Bases

Question 1

The atomic number of an atom refers to its ____.  

A) mass or weight
B) number of protons
C) number of protons and neutrons
D) number of neutrons
E) number of electrons

Answer 1

B

Question 2

Figure 2.5B

Which atom is depicted in the accompanying figure?  

A) Hydrogen
B) Helium
C) Carbon
D) Nitrogen
E) Oxygen

Answer 2

C

Question 3

What is the smallest unit of an element that retains the properties of that element?  

A) Atom
B) Compound
C) Orbital
D) Molecule
E) Mixture

Answer 3

A

Question 4

The ____ of an atom have no charge.  

A) electrons
B) protons
C) neutrons
D) ions
E) nuclei

Question 5

Figure 2.5 C

Which of the following is depicted in the accompanying figure?  

A) Hydrogen atom
B) Sodium atom
C) Helium ion
D) Chlorine ion
E) Oxygen molecule

Question 6

Tracers are elements that ____.  

A) are used in minute amounts in plants
B) can be monitored during biochemical reactions
C) must be inert
D) have an unbalanced electrical charge
E) must have a stable nucleus

Question 7

An atom can get rid of vacancies by participating in a ___________.  

A) cell bond
B) physical bond
C) chemical bond
D) magnetic bond
E) electric bond

Question 8

Figure 2.5A

Based on its outer shell,the atom in the accompanying figure would be characterized as ____.

A) very stable
B) somewhat stable
C) somewhat unstable
D) very unstable
E) radioactive

Question 9

In the chemical shorthand,14C,the 14 represents the number of ____.  

A) excess neutrons
B) protons plus neutrons
C) electrons
D) protons plus electrons
E) radioactive particles

Question 10

The nucleus of an atom contains ____.  

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

Question 11

A(n)__________ is a strong mutual attraction between ions of opposite charge.  

A) ionic bond
B) molecular bond
C) covalent bond
D) polar covalent bond
E) magnetic bond

Question 12

When can we say that atom has no vacancy,or the atom is full?  

A) An atom's outer shell is filled with electrons
B) An atom's inner shell is filled with electrons
C) An atom's outer shell is filled with neutrons
D) An atom's outer shell is filled with protons
E) An atom's inner shell is filled with protons

Question 13

How does the energy of an electron relate with the distance from the nucleus?  

A) The closer an electron is from the nucleus, the greater its energy.
B) The farther an electron is from the nucleus, the greater its energy.
C) The farther a proton is from the nucleus, the greater the electron's energy.
D) The closer a proton is from the nucleus, the greater the electron's energy.
E) The closer a neutron is from the nucleus, the greater the electron's energy.

Question 14

The mass number of an atom is determined by the combined masses of its ____.  

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

Question 15

The ____ of an atom have a negative charge.  

A) nuclei
B) protons
C) neutrons
D) ions
E) electrons

Question 16

Isotopes of atoms ____.  

A) have the same number of neutrons but a different number of protons
B) behave the same chemically and biologically from other isotopes
C) are the same physically and biologically but differ from other isotopes chemically
D) have the same number of protons but a different number of electrons
E) are produced when atoms lose electrons

Question 17

The radioisotope ¹⁴C can be used as a research tracer because it ____.  

A) decays to ¹²C
B) has a different number of protons than ¹²C
C) has fewer neutrons than ¹²C
D) behaves the same chemically as ¹²C
E) has six carbons and six neutrons

Question 18

Isotopes of an element are differentiated by their ____.  

A) atomic weight
B) number of orbital shells
C) element name
D) mass number
E) electron profile

Question 19

All isotopes of an element have a different number of ____.  

A) electrons
B) protons
C) neutrons
D) orbital shells
E) atoms

Question 20

Which substance is not an element?  

A) Chlorine
B) Oxygen
C) Carbon
D) Water
E) Hydrogen

Question 21

"Acidic" is an appropriate description for four of the following.Which one is the exception?  

A) Excess hydrogen ions
B) The contents of the stomach
C) Magnesium hydroxide
D) HCl
E) A pH less than 7

Question 22

A salt will dissolve in water to form ____.  

A) acids
B) only hydrogen and oxygen bonds
C) ions other than H+ and OH-
D) bases
E) buffers

Question 23

The column of water extending in tubes from plant roots to leaves is maintained by ____.  

A) hydrophilic interactions
B) ionic bonds
C) covalent bonds
D) hydrophobic interactions
E) cohesion between water molecules

Question 24

In ____ bonds,both atoms exert the same pull on shared electrons.  

A) triple covalent
B) polar covalent
C) double covalent
D) nonpolar covalent
E) coordinate covalent

Question 25

Atoms with a(n)____ are more likely to form chemical bonds.  

A) filled outer orbital shell
B) unfilled outer orbital shell
C) filled inner orbital shell
D) unfilled inner orbital shell
E) large number of orbital shells

Question 26

When exposed to water,sodium chloride (NaCl)____.  

A) dissolves into Na⁺ and Cl^- ions
B) crystallizes into a solid
C) dissolves into Na^- and Cl⁺ ions
D) crystallizes into a liquid
E) forms a hydrophobic compound

Question 27

Nitrogen,with an atomic number of 7,has ____ electron(s)in the first energy level and ____ electrons in the second energy level.  

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

Question 28

Which statement is false?  

A) A molecule must be made of at least two atoms.
B) Compounds are made of elements.
C) Two atoms of oxygen make a molecule of oxygen.
D) Chemical bonds form between molecules of solute and solvent.
E) Elements are found in compounds and molecules.

Question 29

Water is important to the interactions of biological molecules because it ____.  

A) is a good buffer
B) destabilizes temperature
C) is a poor solvent for polar and ionic substances
D) has weak cohesive properties
E) promotes hydrophilic interactions

Question 30

A molecule consists of ____.  

A) radioactive compounds
B) two or more atoms of the same element
C) electrically charged elements
D) elements with one or more extra neutrons
E) atoms held together by chemical bonds

Question 31

The bond in table salt (NaCl)is ____.  

A) polar
B) ionic
C) covalent
D) double
E) nonpolar

Question 32

Figure 2.11B

The dashed line in the accompanying figure represents a(n)____.  

A) covalent bond
B) ionic bond
C) hydrogen bond
D) polar covalent bond
E) hydrophobic interaction

Question 33

A hydrogen bond is an attraction between a(n)____ hydrogen atom and another atom taking part in ____.  

A) covalently bonded; the same polar covalent bond
B) ionically bonded; the same polar covalent bond
C) covalently bonded; a separate polar covalent bond
D) ionically bonded; a separate nonpolar covalent bond
E) nonpolar covalently bonded; a separate nonpolar covalent bond

Question 34

The most likely reason that glucose dissolves in water is that it is ____.  

A) an ionic compound
B) a polysaccharide
C) polar and forms many hydrogen bonds with the water molecules
D) an extremely unstable molecule
E) highly nonpolar

Question 35

What is a buffer?  

A) A substance that releases hydrogen ions in water
B) A substance that accepts hydrogen ions in water
C) A substance that accepts oxygen ions in water
D) A set of chemicals that keep the pH of a solution stable
E) A substance that releases oxygen ions in water

Question 36

The solvent,cohesive,and temperature stabilization properties of water are primarily due to its ____.  

A) ability to promote hydrophilic interactions
B) ionic bonds
C) hydrogen bonds
D) ability to promote hydrophobic interactions
E) nonpolar nature

Question 37

The slight positive charge of a hydrogen atom in one water molecule is drawn to the slight negative charge of an oxygen atom in another.This interaction is known as a(n)__________.  

A) oxygen bond
B) water bond
C) hydrogen bond
D) covalent polarity bond
E) magnetic bond

Question 38

Which bond can break most easily?  

A) Ionic bond
B) Covalent bonds
C) Polar covalent bond
D) Hydrogen bond
E) Magnetic bond

Question 39

In covalent bonds,____.  

A) atoms share electrons
B) atoms give up electrons
C) atoms accept electrons
D) electrons cannot be shared equally
E) electrons are always shared equally

Question 40

Atoms can form ____ in order to achieve a full outer orbital shell.  

A) ions
B) covalent bonds
C) H bonds
D) ions and covalent bonds
E) ions and H bonds

Question 41

A solution with a pH of 9 has ____ times fewer hydrogen ions than a solution with a pH of 6.  

A) two
B) four
C) 10
D) 100
E) 1,000

Question 42

Classification. The following are important terms relating to water's special properties. Answer the questions below by matching the descriptions with the most appropriate word.
a.hydrophobic
b.hydrophilic
c.salt
d.solute
e.Solvent
A liquid that dissolves other substances

Question 43

¹⁴C is a radioactive isotope,and it turns into ____________________ when it decays.

Question 44

Classification. The following are types of chemical bonds. Answer the questions below by matching the descriptions with the most appropriate bond type.
a.hydrogen
b.ionic
c.covalent
d.polar covalent
e.double bond
The bond that breaks when salts dissolve in water

Question 45

The ability of a solution to resist changes in pH depends on its ____________________ capacity.

Question 46

Blood pH is kept near a value of 7.3-7.5 because of ____.  

A) salts
B) buffers
C) acids
D) bases
E) water

Question 47

Classification. The various energy levels in an atom of magnesium (²⁴Mg) have different numbers of electrons. Use the numbers below to answer the following questions.

-The number of electrons in the second energy level

A)1
B)2
C)3
D)6
E)8

Question 48

Classification. The following are types of chemical bonds. Answer the questions below by matching the descriptions with the most appropriate bond type.

-The bond between the oxygen atoms of oxygen gas (O₂)

A)hydrogen
B)ionic
C)covalent
D)polar covalent
E)double bond

Question 49

Classification. The following are types of chemical bonds. Answer the questions below by matching the descriptions with the most appropriate bond type.
a.hydrogen
b.ionic
c.covalent
d.polar covalent
e.double bond
The bond between the atoms of table salt (NaCl)

Question 50

Classification. The following are important terms relating to water's special properties. Answer the questions below by matching the descriptions with the most appropriate word.
a.hydrophobic
b.hydrophilic
c.salt
d.solute
e.Solvent
Property of NaCl that enables it to dissolve in water

Question 51

Classification. The following are types of chemical bonds. Answer the questions below by matching the descriptions with the most appropriate bond type.
a.hydrogen
b.ionic
c.covalent
d.polar covalent
e.double bond
A bond in which connected atoms unequally share electrons

Question 52

Tracers allow scientists to track a molecule through a biochemical process by replacing an atom in that molecule with its _________.

Question 53

The sharing of two pairs of electrons between two atoms is called a(n)____________________.

Question 54

The predictable rate of ____________________ allows scientists to estimate the age of a rock or fossil by examining its isotope content.

Question 55

Classification. The following are types of chemical bonds. Answer the questions below by matching the descriptions with the most appropriate bond type.
a.hydrogen
b.ionic
c.covalent
d.polar covalent
e.double bond
The bond type holding several molecules of water together

Question 56

Classification. The various energy levels in an atom of magnesium (²⁴Mg) have different numbers of electrons. Use the numbers below to answer the following questions.

-The number of electrons in the third energy level

A)1
B)2
C)3
D)6
E)8

Question 57

Classification. The various energy levels in an atom of magnesium (²⁴Mg) have different numbers of electrons. Use the numbers below to answer the following questions.

-The number of electrons in the first energy level

A)1
B)2
C)3
D)6
E)8

Question 58

Classification. The following are types of chemical bonds. Answer the questions below by matching the descriptions with the most appropriate bond type.
a.hydrogen
b.ionic
c.covalent
d.polar covalent
e.double bond
A bond in which connected atoms share electrons

Question 59

Classification. The following are important terms relating to water's special properties. Answer the questions below by matching the descriptions with the most appropriate word.
a.hydrophobic
b.hydrophilic
c.salt
d.solute
e.Solvent
A compound that releases ions when dissolved in water

Question 60

Classification. The following are important terms relating to water's special properties. Answer the questions below by matching the descriptions with the most appropriate word.
a.hydrophobic
b.hydrophilic
c.salt
d.solute
e.Solvent
NaCl becomes this in solution

Question 61

Classification. The following are important terms relating to acids and bases. Answer the questions below by matching the descriptions with the most appropriate word.
a.pH
b.acid
c.base
d.Buffer
Toothpaste

Question 62

Classification. The following are important terms relating to water's special properties. Answer the questions below by matching the descriptions with the most appropriate word.
a.hydrophobic
b.hydrophilic
c.salt
d.solute
e.Solvent
Property of nonpolar compounds

Question 63

Classification. The following are important terms relating to acids and bases. Answer the questions below by matching the descriptions with the most appropriate word.
a.pH
b.acid
c.base
d.Buffer
Set of chemicals that stabilize pH

Question 64

Classification. The following are important terms relating to acids and bases. Answer the questions below by matching the descriptions with the most appropriate word.
a.pH
b.acid
c.base
d.Buffer
Lemon juice

Question 65

Classification. The following are important terms relating to acids and bases. Answer the questions below by matching the descriptions with the most appropriate word.

-Measure of H⁺ in a fluid

A)pH
B)acid
C)base
D)Buffer

Question 66

Classification. The following are important terms relating to acids and bases. Answer the questions below by matching the descriptions with the most appropriate word.

-Substance that accepts,but does not release,H⁺

A)pH
B)acid
C)base
D)Buffer

Question 67

Classification. The following are important terms relating to acids and bases. Answer the questions below by matching the descriptions with the most appropriate word.

-Substance that releases,but does not accept,H⁺

A)pH
B)acid
C)base
D)Buffer