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

The center of an atom is called the

A)element.
B)electron cloud.
C)nucleus.
D)proton.
E)molecule.

Answer 2

C

Question 3

The chemical behavior of an atom is determined by the

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

Answer 3

C

Question 4

The nucleus of an atom consists of

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

Question 5

The actual mass of an atom is known as its

A)atomic number.
B)atomic weight.
C)mass number.
D)atomic mass unit.
E)element number.

Question 6

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

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

Question 7

Oxygen is required in biological systems for

A)cellular respiration.
B)storage of energy.
C)serving as a structural component of bone.
D)serving as a catalyst.
E)chemical messengers.

Question 8

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 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

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

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

Question 11

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 12

A(n)________ is a pure substance composed of atoms.

A)element
B)compound
C)molecule
D)electron
E)neutron

Question 13

The smallest stable units of matter are

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

Question 14

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 15

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 16

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 17

Which element commonly has only a proton as its nucleus?

A)helium
B)neon
C)argon
D)hydrogen
E)None of the answers is correct.

Question 18

Which of the following lists contains only trace elements?

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

Question 19

Atoms of the same element whose nuclei contain the same number of protons,but different numbers of neutrons,are called

A)isotopes.
B)ions.
C)isomers.
D)trace elements.
E)principal elements.

Question 20

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

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

Question 21

If one pair of electrons is unequally shared between two atoms,a ________ 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 22

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

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

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

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

A)Na⁺
B)Cl^-
C)K⁺
D)HCO₃^-
E)NaCl

Question 25

The molecule H₂ is known as

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

Question 26

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 27

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)It is impossible to determine without more information.

Question 28

The molecule CO₂ is known as

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

Question 29

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 30

The weakest bond between two atoms is the ________ bond.

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

Question 31

Ions with a negative charge are called

A)cations.
B)anions.
C)protons.
D)positrons.
E)polar molecules.

Question 32

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 33

Ions with a + charge are called

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

Question 34

H₂O is an example of a(n)

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

Question 35

The molecule O₂ is known as

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

Question 36

Which of the following is not a cation?

A)Na⁺
B)Cl^-
C)K⁺
D)Ca²⁺
E)Mg²⁺

Question 37

In an aqueous solution,cations are attracted toward

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

Question 38

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 39

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 40

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 41

Chemical reactions that release energy are called

A)energetic.
B)exergonic.
C)endergonic.
D)metabolic.
E)enzymatic.

Question 42

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 43

________ accelerate chemical reactions that occur in the human body.

A)Enzymes
B)Reactants
C)Products
D)Metabolites
E)Nutrients

Question 44

In living cells,complex metabolic reactions proceed in a series of steps called

A)enzymes.
B)a metabolic pathway.
C)catalysts.
D)reactants.
E)products.

Question 45

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 46

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 47

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 48

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

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

Question 49

________ molecules are compounds that contain carbon as the primary structural atom.

A)Complex
B)Inorganic
C)Exergonic
D)Endergonic
E)Organic

Question 50

Kinetic energy is stored as ________ energy when a spring is stretched.

A)chemical
B)work
C)thermal
D)potential
E)motion

Question 51

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 52

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 53

Which of the following is/are inorganic substance(s)?

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

Question 54

The three familiar states of matter listed in order from the least to most thermal energy are

A)gas,solid,liquid.
B)liquid,gas,solid.
C)gas,liquid,solid.
D)solid,gas,liquid.
E)solid,liquid,gas.

Question 55

Chemical reactions that absorb energy are called

A)energetic.
B)exergonic.
C)endergonic.
D)metabolic.
E)enzymatic.

Question 56

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

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

Question 57

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 58

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 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

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

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

Question 61

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 62

________ compounds do not usually contain carbon as a primary structural atom.

A)Complex
B)Inorganic
C)Exergonic
D)Endergonic
E)Organic

Question 63

Which property of water helps keep body temperature stabilized?

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

Question 64

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 65

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 66

An important buffer in body fluids is

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

Question 67

________ are soluble inorganic compounds whose solutions will conduct an electric current.

A)Proteins
B)Lipids
C)Ions
D)Electrolytes
E)Enzymes

Question 68

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 69

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 70

Hydrophilic molecules readily associate with

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

Question 71

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 72

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 73

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

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

Question 74

A(n)________ is a homogeneous mixture containing a solvent and a solute.

A)concoction
B)organic molecule
C)inorganic molecule
D)blend
E)solution

Question 75

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 76

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 77

Molecules that do not readily dissolve in water are called

A)hydrophobic.
B)hydrophilic.
C)electrolytes.
D)isophilic.
E)isophobic.

Question 78

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 79

Which pH is closest to normal blood pH?

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

Question 80

Which of the following statements about water is not correct?

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