Chapter 2 Chemical Basis Of Life Exam Questions

1.

All of the food that we eat, liquids that we drink and medications that we take are 
 

2.

Understanding ________ is essential for understanding anatomy and physiology because body structures and functions result from chemical changes. 
 
________________________________________

3.

Chemistry is the branch of science that deals with the composition of matter. 
 
True    False

4.

Which of the following substances is NOT an element? 
 

5.

Matter is anything that has weight and takes up space.  
 
True    False

6.

________ is defined as anything that has weight and takes up space. 
 
________________________________________

7.

All matter is composed of atoms of fundamental substances called ________. 
 
________________________________________

8.

Which elements make up 95% (by weight) of the human body? 
 

9.

An element with an atomic number of 6 contains 12 protons. 
 
True    False

10.

At present, there are 90 known naturally occurring ________. 
 
________________________________________

11.

Which of the following is the number of elements living organisms require?  
 

12.

The atomic weight of an atom of an element equals the number of neutrons in its nucleus.  
 
True    False

13.

The atomic ________ of an atom of an element equals the number of protons and neutrons in its nucleus. 
 
________________________________________

14.

The number of protons in the atoms of a particular element is called the element's atomic ________. 
 
________________________________________

15.

Each element is composed of characteristic tiny particles called ________. 
 
________________________________________

16.

The parts of an atom that lack an electrical charge are called ________. 
 
________________________________________

17.

When atoms combine with other atoms, interactions occur between their ________ shells. 
 
________________________________________

18.

The electrons of an atom occupy one or more areas of space called 
 

19.

The electrons in the outermost shell of an atom determine its 
 

20.

The atoms of the isotopes of a particular element vary in the number of  
 

21.

Sodium and chloride ions readily combine because they have opposite charges.  
 
True    False

22.

An atom that has gained or lost electrons is called an ion. 
 
True    False

23.

Atoms that gain or lose electrons become electrically charged and are called ________. 
 
________________________________________

24.

The type of chemical bond formed when atoms share electrons is called ________. 
 
________________________________________

25.

The first electron shell of an atom can hold a maximum of 
 

26.

A covalent bond is formed by two atoms that share electrons. 
 
True    False

27.

The molecular formula for compounds like sodium chloride (NaCl) give the relative amounts of each element present. 
 
True    False

28.

The formula H₂O means 
 

29.

If two pairs of electrons are shared, the resulting bond is called a double covalent bond. 
 
True    False

30.

The type of chemical bond formed when ions with opposite electrical charges are attracted to one another is called ________. 
 
________________________________________

31.

The attraction of the positive hydrogen end of a polar molecule to the negative nitrogen or oxygen end of another polar molecule is called a(an) 
 

32.

When two or more atoms bond, they form a new kind of particle called a molecule. 
 
True    False

33.

When atoms of different elements bond, they form molecules called ________. 
 
________________________________________

34.

A molecule of a compound always contains definite kinds and numbers of atoms. 
 
True    False

35.

Water is an example of a compound. 
 
True    False

36.

A molecular formula represents the numbers and types of atoms in a molecule. 
 
True    False

37.

A ________ formula shows how atoms are joined and arranged in various molecules. 
 
________________________________________

38.

If the bonds of a reactant molecule break so that simpler molecules, atoms or ions form, the reaction is an exchange reaction. 
 
True    False

39.

A ________ reaction is symbolized as A+B→AB. 
 
________________________________________

40.

A ________ reaction is symbolized as AB→A+B. 
 
________________________________________

41.

A chemical reaction in which pairs of two different molecules trade positions is called a(an) ________ reaction. 
 

42.

When two or more atoms (reactants) bond to form a more complex structure (product) the reaction is called synthesis. 
 
True    False

43.

The opposite of a decomposition reaction is called a ________ reaction. 
 
________________________________________

44.

A decomposition reaction can be symbolized as ________. 
 

45.

A pH value indicates the hydrogen ion concentration in solutions, including body fluids. 
 
True    False

46.

pH is a measure of _________ ion concentration. 
 
________________________________________

47.

The pH scale ranges from 0 to 14.  
 
True    False

48.

A pH of ___________ is the midpoint of the pH scale and signifies equal numbers of hydrogen and hydroxide ions.  
 
________________________________________

49.

A solution that contains more hydrogen ions than hydroxide ions is _________.  
 
________________________________________

50.

Which term describes a solution that contains more hydroxide ions than hydrogen ions? 
 

51.

Each whole number on the pH scale represents a ________ - fold difference in hydrogen ion concentration. 
 

52.

As hydrogen ion concentration increases, the pH number 
 

53.

A solution that has a pH of 6 has ten times the hydrogen ion concentration of a solution with a pH of 
 

54.

A substance that releases hydrogen ions in water is a base.  
 
True    False

55.

An ________ is defined as a substance that ionizes in water. 
 
________________________________________

56.

An acid is defined as an electrolyte that releases hydroxide ions (OH^-) in water.  
 
True    False

57.

A person has alkalosis if the blood pH  
 

58.

As a group, compounds that release ions when they dissolve in water are called  
 

59.

Chemicals that resist changes in pH are called  
 

60.

Buffers combine with hydrogen ions when H⁺ is in excess or they donate hydroxide ions when H⁺ is depleted.  
 
True    False

61.

________ are chemicals that resist changes in pH. 
 
________________________________________

62.

A salt is a compound composed of oppositely charged ions.  
 
True    False

63.

At the cellular level of organization, biology becomes the study of 
 

64.

Which of the following chemicals is NOT an inorganic substance? 
 

65.

Many inorganic substances dissociate in water to release ions. 
 
True    False

66.

Organic substances always contain the elements hydrogen and ________. 
 
________________________________________

67.

Inorganic substances that usually dissociate in water are called  
 

68.

Water accounts for 2/3 of the weight of an adult human.  
 
True    False

69.

________ is the most abundant compound in living material. 
 
________________________________________

70.

Carbon dioxide is 
 

71.

Certain cellular organelles use oxygen to release energy from glucose. 
 
True    False

72.

Which of the following is NOT organic? 
 

73.

The different types of carbohydrates do NOT include 
 

74.

The building blocks of fat molecules are amino acids.  
 
True    False

75.

________ are lipids used primarily to store energy for cellular activities. 
 
________________________________________

76.

Cholesterol is a protein.  
 
True    False

77.

Steroid molecules have four connected rings of carbon atoms.  
 
True    False

78.

The building blocks of proteins are amino acids.  
 
True    False

79.

________ are the building blocks of nucleic acids. 
 
________________________________________

80.

Proteins include DNA and RNA.  
 
True    False

81.

Neutrons are located in the _________ of an atom and they have a "charge" that is ________. 
 

82.

Electrons are located in the _________ of an atom and they have a "charge" that is ________. 
 

83.

Protons are located in the _________ of an atom and they have a "charge" that is ________. 
 

84.

The branch of science that deals with the composition of matter is ________. 
 

85.

Carbon, oxygen, sodium and hydrogen compose over 95% (by weight) of the human body. 
 
True    False

86.

Atoms of different elements vary in size, weight and ways they interact with atoms or different elements. 
 
True    False

87.

Protons are the subatomic particles that determine an atom's bonding behavior. 
 
True    False

88.

Protons and electrons are similar in size. 
 
True    False

89.

The number of protons plus the number of ________ is approximately equal to the atomic weight. 
 
________________________________________

90.

All isotopes of an element have the same number of electrons. 
 
True    False

91.

Of the three common forms of radiation, _______ radiation is most penetrating and similar to X-rays. 
 
________________________________________

92.

In an atom, the first shell contains a maximum of ________ electrons. 
 
________________________________________

93.

In an atom, the second shell contains a maximum of ________ electrons. 
 
________________________________________

94.

The chemical behavior of atoms results from interactions among their _________. 
 
________________________________________

95.

Atoms that lose or gain electrons become electrically charged particles called __________. 
 

96.

When atoms form bonds by sharing electrons, the bond formed is a type of ________ bond. 
 

97.

In a water molecule, shared electrons spend more time at the oxygen pole than the hydrogen pole, an example of ________ bonds. 
 

98.

The smallest subatomic particle is the ________. 
 
________________________________________

99.

FX --> F + X is an example of a ________ reaction. 
 
________________________________________

100.

X + Y --> XY is an example of a ________ reaction. 
 
________________________________________

101.

In ____________ reactions, parts of one molecule can be removed and added to a different molecule. 
 
________________________________________

102.

Collectively, these bonds are responsible for the surface tension of water, but individually they are weak bonds. 
 

103.

If solution A has a pH of 6 and solution B has a pH of 3, then ________. 
 

104.

________ are chemicals that resist pH changes. 
 
________________________________________

105.

Normal blood pH range is ________. 
 
________________________________________

106.

As the concentration of hydrogen ions increases, a solution's pH decreases. 
 
True    False

107.

Water, salts, oxygen and proteins are all examples of inorganic substances. 
 
True    False