Deck 2: The Chemical Level of Organization

Question 1

Which element commonly has only a proton as its nucleus?

A)helium
B)neon
C)argon
D)hydrogen
E)carbon

Answer 1

D

Question 2

Radioisotopes have unstable

A)ions.
B)nuclei.
C)isotopes.
D)electron clouds.
E)protons.

Answer 2

B

Question 3

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

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

Answer 3

D

Question 4

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 5

The nucleus of an atom consists of

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

Question 6

In any given molecule,the sum of the atomic weights of its component atoms is called

A)molecular mass.
B)molecular weight.
C)atomic mass.
D)atomic weight.
E)chemical mass.

Question 7

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

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

Question 8

The atomic number represents the number of

A)electrons in an atom.
B)protons in an atom.
C)neutrons in an atom.
D)protons and neutrons in an atom.
E)chemical bonds the atom may form.

Question 9

The smallest stable units of matter are

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

Question 10

Which of these lists contains only trace elements?

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

Question 11

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 12

Helium (He)has an atomic number of 2.It is chemically stable because it

A)is neutral in electrical charge.
B)readily ionizes to react with other atoms.
C)has a full outer electron shell.
D)will form a covalent bond with another He atom.
E)lacks electrons,thus the He atom is stable.

Question 13

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

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

Question 14

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 15

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 16

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

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

Question 17

One mole of any element has the same

A)mass.
B)weight.
C)number of atoms.
D)number of electrons.
E)All of the answers are correct.

Question 18

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 19

Given the following approximate values,calculate the molecular weight for NaCl. Atomic number for Na: 11,Atomic weight for Na: 23 g/mol,Atomic number for Cl: 17,
Atomic weight for Cl: 35 g/mol,Boiling point for Cl: -34 °C

A)11 g/mol
B)28 g/mol
C)34 g/mol
D)40 g/mol
E)58 g/mol

Question 20

If an element is composed of atoms with an atomic number of 6 and a mass number of 14,then a non-isotopic 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 neurons.

Question 21

The molecule O₂ is known as

A)oxide.
B)oxygen.
C)organic.
D)oxate.
E)a salt.

Question 22

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 23

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

A)single covalent
B)double covalent
C)triple covalent
D)polar covalent
E)hydrogen

Question 24

Ions in an ionic molecule are held together due to

A)the sharing of electrons.
B)the attraction of opposite electrical charges.
C)each electron orbiting all of the ions in the molecule.
D)the presence of water molecules.
E)the attraction of similar charges of the ions' protons.

Question 25

H₂O is an example of a(n)

A)ionic formula.
B)glucose molecule.
C)compound.
D)ion.
E)covalent formula.

Question 26

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 27

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 28

Ionic bonds are formed when

A)atoms share electrons.
B)an electron or 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 29

When electrons are transferred from one atom to another,and the two atoms unite as a result of the opposite charges,a(n)________ is formed.

A)ion
B)molecule
C)hydrogen bond
D)ionic bond
E)covalent bond

Question 30

The molecule NO is known as

A)nitric oxide.
B)noxious oxide.
C)noxious oxygen.
D)nitric oxygen.
E)nitrous oxide.

Question 31

The molecule H₂ is known as

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

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

Which of the following is not a cation?

A)Na⁺
B)Cl⁻
C)K⁺
D)Ca²⁺
E)Mg²⁺

Question 34

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 35

The molecule CO₂ is known as

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

Question 36

The weakest bond between two atoms is the ________ bond.

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

Question 37

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 38

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.

Question 39

In an aqueous solution,cations are attracted toward

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

Question 40

Ions with a + charge are called

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

Question 41

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

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

Question 42

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 43

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

A)Na⁺
B)Cl⁻
C)K⁺
D)HCO₃⁻
E)NaCl

Question 44

Which of the following descriptors is false regarding enzymes?

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

Question 45

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

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

Question 46

Which one of the following statements is false 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 47

Each of the following is an inorganic compound except

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

Question 48

In an ionic bond,the electron donor is the ________,whereas the electron acceptor is the ________.

A)acid; base
B)salt; ion
C)anion; cation
D)base; acid
E)cation; anion

Question 49

Oxygen (atomic number 8)requires how many additional electrons to fill its outer electron shell?

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

Question 50

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 51

The formula for methane gas is CH₄.What does the formula 4CH₄ represent?

A)a molecule with 4 carbon atoms
B)a molecule with 4 carbon atoms and 16 hydrogen atoms
C)4 molecules,each containing a carbon and a hydrogen atom
D)4 molecules,each containing a carbon atom and 4 hydrogen atoms
E)an inorganic compound with ionic bonds

Question 52

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 53

In a molecule of nitrogen,three pairs of electrons are shared by two nitrogen atoms.The type of bond that is formed is an example of a ________ bond.

A)single trivalent
B)double divalent
C)triple covalent
D)polar covalent
E)hydrogen

Question 54

Magnesium atoms have two electrons in the outermost shell 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 55

Sodium (Na)has an atomic number of 1 1.How many electrons are in the outer electron shell of a neutral sodium atom?

A)1
B)2
C)3
D)4
E)8

Question 56

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 57

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

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

Question 58

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

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

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

In dehydration synthesis 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 61

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 62

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 63

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 64

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

A)break chemical bonds.
B)change the shape of proteins,rendering them nonfunctional.
C)disrupt tissue functions.
D)change body fluid pH.
E)All of the answers are correct.

Question 65

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

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

Question 66

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)There is not enough information to determine the answer.

Question 67

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

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

Question 68

In the body,inorganic compounds

A)can serve as buffers.
B)can make up proteins.
C)are made from organic compounds.
D)are structural components of cells.
E)are metabolized for cellular energy.

Question 69

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)counterions.

Question 70

An example of an inorganic substance is

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

Question 71

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 72

Which pH is closest to normal body pH?

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

Question 73

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 74

The chemical notation that indicates concentration is represented as

A)().
B)<>.
C)[ ].
D){}.
E)||.

Question 75

Which of the following has the highest concentration of hydroxide ions?

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

Question 76

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 77

Which of the following statements about water is false?

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.

Question 78

Which property of water helps keeps body temperature stabilized?

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

Question 79

Hydrophilic molecules readily associate with

A)lipid molecules.
B)hydrophobic molecules.
C)water molecules.
D)acids.
E)salts.

Question 80

An important buffer in body fluids is

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