Deck 2: Chemical Level of Organization

Question 1

If an element is composed of atoms with an atomic number of 6 and a mass number of 14, then the nucleus of a neutral atom of this element contains

A) 6 protons.
B) 8 electrons.
C) 8 neutrons.
D) 6 protons and 8 electrons.
E) 6 protons and 8 neutrons.

Answer 1

E

Question 2

Oxygen is required in biological systems for

A) cellular respiration.
B) storage of energy.
C) serving as structural components of bone.
D) serving as catalysts.
E) chemical messengers.

Answer 2

A

Question 3

Which of the following is not a cation?

A) Na⁺
B) Cl⁻
C) K⁺
D) Ca²⁺
E) Mg²⁺

Answer 3

B

Question 4

Elements that have atoms with full outer shells of electrons

A) will form many compounds.
B) will normally form anions.
C) will normally form cations.
D) frequently form hydrogen bonds.
E) are inert gases.

Question 5

The innermost electron shell in an atom holds up to ________ electrons.

A) 1
B) 2
C) 4
D) 6
E) 8

Question 6

Ions with a + charge are called

A) cations.
B) anions.
C) radicals.
D) positrons.
E) isotopes.

Question 7

If an isotope of oxygen has 8 protons, 10 neutrons, and 8 electrons, its mass number is ________.

A) 26
B) 16
C) 18
D) 8
E) 12

Question 8

By weight, which element is the most plentiful in the human body?

A) sulfur
B) sodium
C) oxygen
D) potassium
E) carbon

Question 9

The mass of an atom is largely determined by the number of ________ it has.

A) electrons
B) protons
C) neutrons
D) protons + neutrons
E) protons + electrons

Question 10

The "atomic weight" of an atom reflects the average number of

A) protons.
B) neutrons.
C) electrons.
D) protons + neutrons.
E) protons + neutrons + electrons.

Question 11

The mass number represents the number of

A) protons in an atom.
B) electrons in an ion.
C) neutrons in an atom.
D) protons + neutrons.
E) neutrons + electrons.

Question 12

The "atomic number" of an atom is determined by the number of ________ it has.

A) electrons
B) protons
C) neutrons
D) protons + neutrons
E) protons + electrons

Question 13

Isotopes of an element differ in the number of

A) protons in the nucleus.
B) electrons in the nucleus.
C) neutrons in the nucleus.
D) electron clouds.
E) electrons in energy shells.

Question 14

Which element commonly has only a proton as its nucleus?

A) helium
B) neon
C) argon
D) hydrogen
E) none of the above

Question 15

In an aqueous solution, cations are attracted toward

A) water.
B) salt.
C) buffers.
D) anions.
E) hydrogen ions.

Question 16

The chemical behavior of an atom is determined by

A) the number of protons.
B) the number of neutrons.
C) the outermost electron shell.
D) the size of the atom.
E) the mass of the nucleus.

Question 17

By weight, which element is the second most abundant in the human body?

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

Question 18

Which of the following lists contain only trace elements?

A) sulfur, chlorine, oxygen
B) selenium, hydrogen, calcium
C) boron, oxygen, carbon
D) silicon, fluorine, tin
E) cobalt, calcium, sodium

Question 19

The smallest stable units of matter are

A) atoms.
B) molecules.
C) protons.
D) neutrons.
E) electrons.

Question 20

The nucleus of an atom consists of

A) electrons.
B) protons.
C) neutrons.
D) protons + neutrons.
E) protons + electrons.

Question 21

In a molecule of oxygen gas, two pairs of electrons are shared equally by two oxygen atoms. The type of bond that is formed is an example of a(n)

A) single trivalent bond.
B) double nonpolar covalent bond.
C) triple nonpolar covalent bond.
D) double polar covalent bond.
E) hydrogen bond.

Question 22

The reaction N₂ + 3 H₂ → 2 NH₃ is an example of a(n)

A) exchange reaction.
B) decomposition reaction.
C) synthesis reaction.
D) enzyme reaction.
E) metabolic reaction.

Question 23

Magnesium atoms have two electrons in the outermost shell. As a result, you would expect magnesium to form ions with a charge of

A) +1.
B) +2.
C) -1.
D) -2.
E) either +2 or -2

Question 24

In the reaction listed below, what coefficient needs to be added to balance the equation?
6 CO₂ + 6 H₂O → C₆H₁₂O₆ + _____ O₂

A) 2
B) 4
C) 6
D) 8
E) 10

Question 25

Ionic bonds are formed when

A) atoms share electrons.
B) electrons are completely transferred from one atom to another.
C) a pair of electrons is shared unequally by two atoms.
D) hydrogen forms bonds with negatively charged atoms.
E) two or more atoms lose electrons at the same time.

Question 26

When atoms complete their outer electron shell by sharing electrons, they form

A) ionic bonds.
B) covalent bonds.
C) hydrogen bonds.
D) anions.
E) cations.

Question 27

AB → A + B is to decomposition as A + B → AB is to

A) exchange.
B) synthesis.
C) combustion.
D) replacement.
E) metabolism.

Question 28

H₂O is an example of a(n)

A) ionic formula.
B) glucose molecule.
C) molecular formula.
D) water molecule.
E) covalent formula.

Question 29

The molecule CO₂ is known as

A) carbonized oxygen.
B) carbonated oxygen.
C) carbon monoxide.
D) carbon oxide.
E) carbon dioxide.

Question 30

Which one of the following statements is not correct about the reaction H₂ + Cl₂ → 2 HCl?

A) H₂ and Cl₂ are the reactants.
B) HCl is the product.
C) One molecule of hydrogen contains two atoms.
D) Two molecules of HCl are formed in the reaction.
E) This reaction is easily reversible.

Question 31

Magnesium atoms have two electrons in their outermost shells and chlorine atoms have seven. The compound magnesium chloride would contain

A) 1 magnesium and 1 chlorine.
B) 1 magnesium and 2 chlorine.
C) 2 magnesium and 1 chlorine.
D) 2 magnesium and 7 chlorine.
E) impossible to tell without more information

Question 32

Which of the following statements about hydrogen bonds is False ?

A) Hydrogen bonds are strong attractive forces between hydrogen atoms and negatively charged atoms.
B) Hydrogen bonds can occur within a single molecule.
C) Hydrogen bonds can form between neighboring molecules.
D) Hydrogen bonds are important for holding large molecules together.
E) Hydrogen bonds are responsible for many of the properties of water.

Question 33

The molecule H₂ is known as

A) hydrohydrogen.
B) hydrogen.
C) hydroxide.
D) helium.
E) semi-water.

Question 34

Which of the following is both an anion and a compound?

A) Na⁺
B) Cl⁻
C) K⁺
D) HCO₃⁻
E) NaCl

Question 35

The weakest bond between two atoms is the ________ bond.

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

Question 36

In an aqueous solution, sodium ions would move toward

A) a negative terminal.
B) a positive terminal.
C) a pH terminal.
D) an organic terminal.
E) the bottom.

Question 37

The molecule O₂ is known as

A) oxide.
B) oxygen.
C) organic.
D) oxygen and organic.
E) oxyous.

Question 38

When electrons are transferred from one atom to another, and the two atoms unite as a result of the opposite charges,

A) an ion is formed.
B) a free electron is formed.
C) a hydrogen bond is formed.
D) an ionic bond is formed.
E) a covalent bond is formed.

Question 39

If one pair of electrons is unequally shared between two atoms, a(n) ________ occurs.

A) single nonpolar covalent bond
B) double nonpolar covalent bond
C) double polar covalent bond
D) single polar covalent bond
E) hydrogen bond

Question 40

In chemical notation, the symbol Ca²⁺ means ________.

A) two calcium atoms
B) a calcium ion that has lost two electrons
C) a calcium ion that has gained two protons
D) a calcium ion that has gained two electrons
E) a calcium ion that has lost two protons

Question 41

In dehydration reactions, compounds

A) lose water molecules.
B) gain water molecules.
C) convert water molecules to hydrogen and oxygen.
D) convert hydrogen and oxygen to water.
E) gain electrons.

Question 42

An example of an inorganic substance is (are)

A) fructose.
B) water.
C) glycerol.
D) carbon dioxide.
E) both water and carbon dioxide.

Question 43

A dust particle floating on a water surface illustrates

A) surface tension.
B) chemical tension.
C) static electricity.
D) heat capacity.
E) hydrophilic attraction.

Question 44

During ionization, water molecules disrupt the ionic bonds of a salt to produce a mixture of ions. These ions can carry a current and so are called

A) cations.
B) anions.
C) acids.
D) electrolytes.
E) counter ions.

Question 45

Nonpolar organic molecules are good examples of

A) electrolytes.
B) molecules that will dissociate when placed into water.
C) hydrophobic compounds.
D) hydrophilic compounds.
E) solutes.

Question 46

Substrate molecules bind to enzymes at the ________ sites.

A) amino
B) active
C) carboxyl
D) reactant
E) neutral

Question 47

Chemical reactions that yield energy, such as heat, are said to be

A) endergonic.
B) activated.
C) exergonic.
D) neutral.
E) thermonuclear.

Question 48

The reaction A + B + energy → AB is an example of a(n)

A) exergonic reaction.
B) endergonic reaction.
C) equilibrium reaction.
D) decomposition reaction.
E) exchange reaction.

Question 49

Which of the following statements about water is not correct?

A) is composed of polar molecules
B) is responsible for much of the mass of the human body
C) has a relatively low heat capacity
D) can dissolve many substances
E) contains hydrogen bonds

Question 50

Hydrophilic molecules readily associate with

A) lipid molecules.
B) hydrophobic molecules.
C) water molecules.
D) both lipid molecules and hydrophobic molecules.
E) cholesterol.

Question 51

All of the following are True concerning enzymes, except that they

A) are proteins.
B) function as biological catalysts.
C) lower the activation energy required for a reaction.
D) affect only the rate of a chemical reaction.
E) are consumed during the reaction.

Question 52

An important buffer in body fluids is

A) NaCl.
B) NaOH.
C) HCl.
D) NaHCO₃.
E) H₂O.

Question 53

Each of the following is an example of an inorganic compound, except

A) water.
B) acids.
C) bases.
D) salts.
E) proteins

Question 54

Compounds that can be synthesized or broken down by chemical reactions inside the body are called

A) inorganic compounds.
B) organic compounds.
C) nutrients.
D) metabolites.
E) enzymes.

Question 55

Which of the following substances would be most acidic?

A) lemon juice, pH = 2
B) urine, pH = 6
C) tomato juice, pH = 4
D) white wine, pH = 3
E) stomach secretions, pH = 1

Question 56

Which property of water helps keep body temperature stabilized?

A) kinetic energy
B) lubrication
C) surface tension
D) reactivity
E) thermal inertia

Question 57

If a substance has a pH that is greater than 7, it is

A) neutral.
B) acidic.
C) alkaline.
D) a buffer.
E) a salt.

Question 58

Oppositely charged ions in solution are prevented from combining by

A) heat capacity of water.
B) hydration spheres.
C) water's nonpolar nature.
D) free radicals.
E) hydrogen bonding.

Question 59

In hydrolysis reactions, compounds react with

A) hydrogen, causing decomposition.
B) glucose, causing decomposition.
C) water, causing decomposition.
D) carbon, causing decomposition.
E) water, causing synthesis.

Question 60

A solution containing equal numbers of hydrogen ions and hydroxide ions is

A) acidic.
B) basic.
C) neutral.
D) alkaline.
E) in equilibrium.

Question 61

An excess of hydrogen ions in the body fluids can have fatal results because this can

A) block ion movements.
B) change the shape of large complex molecules, rendering them nonfunctional.
C) disrupt tissue functions.
D) all of the above
E) none of the above

Question 62

In the body, inorganic compounds

A) can serve as buffers.
B) can make up proteins.
C) can make up lipids.
D) are structural components of cells.
E) are all very large.

Question 63

Carbohydrate molecules

A) are the building blocks of cellular membranes.
B) form the regulatory molecules known as enzymes.
C) are the body's most readily available source of energy.
D) are composed of C, H, O, and N atoms.
E) contain the genetic information found in cells.

Question 64

When two monosaccharides undergo a dehydration synthesis,

A) two new monosaccharides are formed.
B) a disaccharide is formed.
C) a polysaccharide is formed.
D) a starch is formed.
E) all of the above

Question 65

A(n) ________ removes hydrogen ions and a(n) ________ releases hydrogen ions.

A) acid; base
B) base; acid
C) compound; element
D) element; compound
E) molecule; acid

Question 66

Molecules that have the same molecular formula but different structural formulas are called

A) isotopes.
B) isomers.
C) isozymes.
D) isotypes.
E) isomoles.

Question 67

When a small amount of HCl or NaOH is added to a solution of Na₂HPO₄, the pH of the solution barely changes. Based on these observations, all of the following are True concerning the compound Na₂HPO₄, except

A) Na₂HPO₄ is able to accept extra hydrogen ions from the HCl.
B) Na₂HPO₄ is able to donate hydrogen ions to the OH⁻ from NaOH.
C) Na₂HPO₄ adsorbs excess H⁺ and OH⁻ directly onto the surface of its crystalline structure.
D) Na₂HPO₄ is a salt formed from reacting a strong base with a weak acid.
E) Na₂HPO₄ acts as a buffer.

Question 68

An example of an organic substance is

A) sucrose.
B) carbonic acid.
C) sodium chloride.
D) oxygen.
E) carbon dioxide.

Question 69

The group of organic compounds containing carbon, hydrogen, and oxygen in a near 1:2:1 ratio is defined as a

A) carbohydrate.
B) lipid.
C) protein.
D) nucleic acid.
E) cholesterol.

Question 70

The most important metabolic fuel molecule in the body is

A) sucrose.
B) caffeine.
C) protein.
D) vitamins.
E) glucose.

Question 71

Of the list below, which has the highest concentration of hydroxide ions?

A) pH 1
B) pH 14
C) pH 7
D) pH 10
E) pH 2

Question 72

Carbohydrates, lipids, and proteins are classified as

A) organic molecules.
B) inorganic molecules.
C) acids.
D) salts.
E) bases.

Question 73

Which has the greater concentration of hydrogen ions, a substance with a pH of 5 or a substance with a pH of 4?

A) A pH of 4 is greater.
B) A pH of 5 is greater.
C) They are both equal; 4 and 5 are relative values.
D) pH 9, if you mixed the solutions.
E) Neither, pH has nothing to do with hydrogen ion concentration.

Question 74

Which of the following is the symbol for an amino group?

A) -COOH
B) -PO₃
C) -NH₂
D) -AMO
E) -OH

Question 75

A functional group is best described as reoccurring clusters of

A) elements that occur in a salt.
B) atoms that greatly influence the chemical properties of molecules they are part of.
C) atoms that function in the body.
D) elements that form at high pH.
E) amino acids in a globular protein.

Question 76

Which pH is closest to normal blood pH?

A) pH 7
B) pH 8
C) pH 4
D) pH 3
E) pH 2

Question 77

Of the following choices, the pH of the least acidic solution is

A) 6.0.
B) 4.5.
C) 2.3.
D) 1.0.
E) 12.0.

Question 78

A polysaccharide that is formed in liver and muscle cells to store glucose is

A) lactose.
B) cellulose.
C) glycogen.
D) sucrose.
E) fructose.

Question 79

When placed in water, an inorganic compound dissociates 99 percent, forming hydrogen ions and anions. This compound would be

A) a strong base.
B) a weak base.
C) a strong acid.
D) a weak acid.
E) a salt.

Question 80

Fructose

A) is a hexose.
B) is an isomer of glucose.
C) is found in fruits.
D) all of the above
E) none of the above