Deck 2: Atoms and Molecules: the Chemical Basis of Life

Question 1

The difference between a stable isotope and a radioisotope is that:

A) the stable isotope emits radiation.
B) the radioisotope emits radiation.
C) the stable isotope emits light.
D) the stable isotope absorbs radiation.
E) the radioisotope has an unequal number of protons and electrons.

Answer 1

B

Question 2

Any chemical interaction between atoms:

A) involves neutrons.
B) may potentially involve any electron.
C) involves protons.
D) involves only valence electrons.
E) involves only the nuclear subatomic particles.

Answer 2

D

Question 3

Which of the following statements is FALSE?

A) The 1^st principal energy level contains 1 orbital.
B) The 2^nd principal energy level contains 4 orbitals.
C) The 1^st principal energy level contains a maximum of 2 electrons.
D) The 2^nd energy level contains a maximum of 10 electrons.
E) The 2^nd energy level contains 1 spherical orbital and 3 dumbbell-shaped orbitals..

Answer 3

D

Question 4

The chemical behavior of an atom is determined by most directly by the:

A) atomic number.
B) atomic weight.
C) number of energy levels.
D) number of valence electrons.
E) number of neutrons.

Question 5

The representation H-O-H is known as:

A) a structural formula.
B) a simplest formula.
C) a molecular formula.
D) a Lewis structure.
E) an orbital diagram.

Question 6

Figure 2-1
Use the figure below to answer the corresponding question(s).
Isotopes differ from each other with respect to the number of:

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

Question 7

An element is defined as a substance that:

A) is composed of more than one kind of atom.
B) is held together by covalent bonds.
C) cannot be broken into simpler substances by chemical reactions.
D) cannot burn.
E) is soluble in both acid and base.

Question 8

How many molecules are present in one mole of C₆H₁₂O₆?

A) 1.7 *10^-10 molecules
B) 1.3 F* 10¹⁰ molecules
C) 24 molecules
D) 1.7 * 10²² molecules
E) 6.02 * 10²³ molecules

Question 9

The particular type of element is determined by the number of:

A) electrons
B) protons
C) neutrons
D) valence electrons
E) energy levels

Question 10

Figure 2-1
Use the figure below to answer the corresponding question(s).
The difference between the two atoms in Figure 2-1 is:

A) pH.
B) the number of electrons.
C) the number of protons.
D) the number of neutrons.
E) electrical charge.

Question 11

If atom X contains 14 protons, 13 electrons, and 12 neutrons, and atom Y contains 14 protons, 14 electrons, and 12 neutrons, then you conclude that:

A) Y is an ion but X is not.
B) X and Y are both ions.
C) X and Y both have filled valence shells.
D) X and Y are isotopes of the same element.
E) X and Y are atoms of the same element.

Question 12

In a chemical reaction, the product is:

A) generally written on the right side of the equation.
B) always in equilibrium with the reactants.
C) the substance that is generated by the reaction.
D) joined by an ionic bond only.
E) generally written on the right side and is the substance generated by the reaction.

Question 13

An atom has six protons and eight neutrons.Its atomic mass is __________ atomic mass units.

A) two
B) four
C) six
D) eight
E) fourteen

Question 14

Which of the following choices correctly identifies a reactant in the following chemical equation? CO₂ + H₂O $\harr$ H₂CO₃

A) carbonic acid
B) oxygen
C) water
D) sugar
E) carbon monoxide

Question 15

An organic compound differs from an inorganic compound in that an organic compound:

A) contains carbon.
B) contains two or more atoms.
C) lacks valence electrons.
D) lacks isotopes.
E) is basic rather than acidic.

Question 16

Figure 2-1
Use the figure below to answer the corresponding question(s).
Figure 2-1 represents:

A) two isotopes of the same element.
B) two different elements.
C) two different ions.
D) an acid and a base.
E) a cation and an anion.

Question 17

Which of the following elements is NOT responsible for a significant portion of the mass of living organisms?

A) O
B) S
C) N
D) H
E) C

Question 18

Chlorine has seven electrons in its valence shell.The number of electrons it must gain to complete its valence shell is:

A) one.
B) two.
C) three.
D) seven.
E) eight.

Question 19

When a chemical reaction is at equilibrium:

A) the forward reaction is going faster.
B) the reverse reaction is going faster.
C) the forward and reverse reactions are proceeding at equal rates.
D) the forward reaction stops.
E) the reverse reaction stops.

Question 20

Radioisotopes are used in all of the following scientific applications except:

A) dating fossils.
B) determining the sequence of genetic information in DNA.
C) localization of a drug, such as marijuana.
D) the treatment of cancer.
E) measuring the pH of the blood.

Question 21

The difference between an electrically neutral atom and an ion is that:

A) an ion has an unequal number of protons and electrons, while an atom has an equal number.
B) an ion has an equal number of protons and electrons, while an atom has an unequal number.
C) an atom has an unequal number of neutrons and protons, while an ion has an equal number.
D) an atom has its electrons in orbitals, while an ion has its electrons in its nucleus.
E) an atom must have an equal number of neutrons and electrons, while an ion does not.

Question 22

In the formation of common table salt, sodium and chlorine interact because:

A) sodium and chlorine share a pair of electrons.
B) sodium and chlorine share two pairs of electrons.
C) chlorine donates seven electrons to sodium.
D) there is no electron exchange.
E) sodium donates one electron to chlorine.

Question 23

The cohesiveness between water molecules is due largely to:

A) hydrogen bonds.
B) polar covalent bonds.
C) nonpolar covalent bonds.
D) ionic bonds.
E) hydrophobic interactions.

Question 24

Which of the following statements concerning van der Waal interactions is FALSE:

A) They are attractive forces.
B) They are very strong.
C) They involve transient regions of positive and negative charges.
D) They form between nonpolar molecules.
E) They operate over very short distances.

Question 25

Which component becomes oxidized in the following chemical reaction? 4 Fe + 3 O₂ $\rightarrow$ 2 Fe₂O₃

A) water
B) iron
C) oxygen
D) rust
E) hydrogen

Question 26

Which component is the oxidizing agent in the following chemical reaction? 4 Fe + 3 O₂ $\rightarrow$ 2 Fe₂O₃

A) water
B) iron
C) oxygen
D) rust
E) hydrogen

Question 27

Figure 2-2
Use the figure below to answer the corresponding question(s).
Figure 2-2 represents:

A) elemental helium.
B) molecular hydrogen.
C) molecular helium.
D) a water molecule.
E) molecular oxygen.

Question 28

Table salt dissolves easily in water because:

A) water can form covalent linkages with salt molecules.
B) water can remove electrons from the chloride ion, which causes the latter to dissociate from the sodium and dissolve.
C) water can add electrons to the sodium ion.
D) water is polar and salt is nonpolar.Nonpolar compounds are more soluble in polar solvents because they are able to form strong covalent bonds that result in a breaking up of the molecule being dissolved.
E) the partial positive charge of the hydrogens in the water molecule can associate with the negative charge of the chloride ion, and the partial negative charge of the oxygen of the water molecule can associate with the positive charge of the sodium atom.

Question 29

The process whereby water molecules surround ions during the process of dissolving is called:

A) reduction.
B) hydration.
C) buffering.
D) oxidation.
E) vaporization.

Question 30

The covalent bond between a hydrogen atom and the oxygen atom in water is formed when:

A) hydrogen gains an electron from oxygen.
B) hydrogen and oxygen share an electron pair.
C) hydrogen and oxygen both lose electrons from their outer shells.
D) hydrogen and oxygen both gain electrons in their outer shells.
E) hydrogen gains an electron from oxygen.

Question 31

A covalent bond:

A) forms only between identical atoms.
B) involves a sharing of only one pair of electrons.
C) is always polar.
D) may be polar or nonpolar depending on the atoms involved.
E) always forms between identical molecules.

Question 32

Figure 2-2
Use the figure below to answer the corresponding question(s).
The type of bond illustrated in Figure 2-2 is:

A) an ionic bond.
B) a polar bond.
C) a single covalent bond.
D) a hydrogen bond.
E) a double covalent bond.

Question 33

A stalk of celery is placed in a solution of blue colored dye.After one hour, the leaves have blue fluid in their veins.Which property of water is being demonstrated?

A) adhesion and cohesion
B) evaporation and cooling
C) lower density as a solid than as a liquid
D) high specific heat
E) surface tension

Question 34

Which of the following statements is not correct?

A) Water heats up and cools down very quickly.
B) The amount of heat required to raise the temperature of 1 g of water 1 $\degree$ C is one calorie.
C) Due to hydrogen bonds, water has a high surface tension.
D) Large bodies of water have relatively constant temperatures.
E) When one gram of water evaporates, it removes heat.

Question 35

Which covalent bond involves only 2 electrons:

A) single
B) double
C) triple
D) single and double.
E) single and triple.

Question 36

In a water molecule, because oxygen is more electronegative than hydrogen, the shared electrons are more commonly found around the __________ nucleus than the __________ nucleus.

A) oxygen; hydrogen
B) hydrogen; oxygen
C) hydrogen; other hydrogen
D) oxygen; nitrogen
E) nitrogen; oxygen

Question 37

Which of the following atoms would most likely be involved in an ionic bond?

A) hydrogen
B) oxygen
C) sodium
D) hydrogen and oxygen.
E) hydrogen and sodium.

Question 38

Covalently bonded atoms with similar electronic negativities are:

A) ionic.
B) polar.
C) nonpolar.
D) partially positive.
E) partially negative.

Question 39

An atom becomes a cation if:

A) it gains one or more electron.
B) it loses one or more electron.
C) it shares electrons.
D) one or more of its electrons changes energy levels.
E) it emits radiation.

Question 40

Which characteristic of water molecules directly contributes to the remarkable "water walking" success of the aquatic insects pictured in the accompanying figure?

A) hydrogen bonds
B) capillary action
C) nonpolar covalent bonds
D) ionic bonds
E) adhesive forces

Question 41

Which characteristic of water makes the existence of pH possible?

A) ionization
B) polarity
C) adhesion
D) cohesion
E) hydrophobicity

Question 42

At what temperature is water most dense?

A) 0 degrees Celsius
B) 1 degree Celsius
C) 4 degrees Celsius
D) 10 degrees Celsius
E) 100 degrees Celsius

Question 43

Explain how the number of valence electrons is related to the chemical properties of an atom.Use two specific examples in your explanation.

Question 44

This characteristic of a molecule determines the ability of hydrogen bonds to form between it and hydrogen:

A) A nonpolar atom.
B) An atom with a partial positive charge.
C) An atom with a partial negative charge.
D) A hydrophobic molecule.
E) An atom with a filled valence shell.

Question 45

Compare and contrast the formation, properties, and characteristics of covalent and ionic bonds.

Question 46

In a mixture, which would be present in the least amount?

A) solvent
B) solute
C) water
D) both solvent and solute
E) both solvent and water

Question 47

Evaporative cooling is a process whereby __________ moving __________ molecules vaporize, thus __________ large amounts of heat.

A) slow; water; adding
B) fast; water; removing
C) slow; oxygen; adding
D) fast; oxygen; removing
E) fast; carbon dioxide; removing

Question 48

Diagram and carefully label two water molecules using a ball-and-stick model.Then use this diagram to demonstrate how hydrogen bonds form between them.

Question 49

Identify the chemical(s) that act(s) as a buffer in human blood:

A) bicarbonate
B) hydrogen ions
C) carbon dioxide
D) water
E) hydroxide ions

Question 50

What is the OH ^-- concentration of a solution having a pH of 2?

A) 1 *10^-12
B) 1 *10^-10
C) 1 *10^-7
D) 1* 10^-2
E) 1 *10^-1

Question 51

When a small amount of hydrochloric acid (HCl) is added to a solution of Na₂HPO₄, the pH of the solution does not change markedly.The pH also does not change drastically when a small amount of sodium hydroxide (NaOH) is added to this same solution.Based on these observations, the compound Na₂HPO₄ is:

A) able to donate hydrogen atoms to HCl.
B) able to remove hydrogen ions from the OH ^- of NaOH.
C) acting as a buffer.
D) an enzyme facilitating the reaction between HCl and NaOH.
E) acting as a solvent.

Question 52

List the four elements that account for over 90% of the mass of living organisms and identify an important biological function of each element.

Question 53

Which of the following would most likely form electrolytes in water?

A) glucose
B) ethanol
C) an organic compound
D) an inorganic compound
E) a nonionic compound

Question 54

A salt is a compound in which the hydrogen ion of __________ is replaced by some other cation.

A) a base
B) an acid
C) an anion
D) a hydroxide ion
E) water

Question 55

Identify the hydrogen ion concentration that represents the lowest pH from the following list:

A) 1 *10 ^{- 3}
B) 1 * 10^{- 4}
C) 1 * 10 ^{- 7}
D) 1 *10^-11
E) 1 *10^-14

Question 56

Which of the following has a pH closest to that of human blood?

A) beer
B) coffee
C) rain water
D) sea water
E) oven cleaner

Question 57

A solution having a pH of 6 would:

A) have equal concentrations of hydrogen ions and hydroxide ions.
B) have a higher concentrations of hydroxide ions than hydrogen ions.
C) be slightly acidic.
D) be slightly basic.
E) be neutral.

Question 58

It takes 1 calorie of heat to raise the temperature of 1 gram of water 1 degree Celsius at sea level.This is referred to as the __________ of water.

A) heat of fusion
B) heat of vaporization
C) specific heat
D) heat of transformation
E) heat of homeostasis

Question 59

Which property of water enables living things to survive in ponds covered with ice?

A) high heat of vaporization
B) high specific heat
C) degree of surface tension
D) cohesion
E) greatest density at 4^oC

Question 60

A pH of 4 is __________ times more __________ than a pH of 7.

A) 3; basic
B) 3; acidic
C) 1000; neutral
D) 1000; basic
E) 1000; acidic

Question 61

MATCHING
Match the type of bond or interaction with its description.
a.hydrogen bond
c.ionic bond
b.van de Waals interaction
d.covalent bond
Strong attractive force resulting from the transfer of electrons between atoms

Question 62

Match the term with its description:
a.adhesion
c.surface tension
b.cohesion
d.capillary action
Responsible for the ability of water molecules to move in the microscopic spaces between soil particles

Question 63

The tetrahedron shape of a methane molecule is the result of orbital hybridization.
__________________

Question 64

MATCHING
Match the type of bond or interaction with its description.
a.hydrogen bond
c.ionic bond
b.van de Waals interaction
d.covalent bond
In a structural formula this is represented by a straight line

Question 65

A solution having a pH of 8 is slightly acidic.
__________________

Question 66

Specific heat refers to the amount of energy required to change 1 gram of a substance from the liquid phase to the vapor phase.
__________________

Question 67

Water is most dense at 4 C.
__________________

Question 68

MATCHING
Match the type of bond or interaction with its description.
a.hydrogen bond
c.ionic bond
b.van de Waals interaction
d.covalent bond
Very weak attractive force joining nonpolar molecules

Question 69

An example of an anion is K⁺.
__________________

Question 70

MATCHING
Match the type of bond or interaction with its description.
a.hydrogen bond
c.ionic bond
b.van de Waals interaction
d.covalent bond
Holds adjacent water molecules together

Question 71

Match the term with its description:
a.adhesion
c.surface tension
b.cohesion
d.capillary action
Directly responsible for the ability of certain insects to walk on water

Question 72

An inorganic compound is one that contains carbon.
__________________

Question 73

MATCHING
Match the type of bond or interaction with its description.
a.hydrogen bond
c.ionic bond
b.van de Waals interaction
d.covalent bond
Strong attractive force resulting from the sharing of electrons between atoms

Question 74

An atom having a filled valence shell is stable and unreactive.
__________________

Question 75

The atomic mass determines the type of element.
__________________

Question 76

MATCHING
Match the type of bond or interaction with its description.
a.hydrogen bond
c.ionic bond
b.van de Waals interaction
d.covalent bond
Weak attractive force joining a hydrogen atom with an electronegative atom such as oxygen

Question 77

A substance that is resistant to changes in pH is called a buffer.
__________________

Question 78

Oxidation occurs when an atom gains one or more electrons.
__________________

Question 79

When atoms react to form an ionic bond, electrons are shared between those atoms.
__________________

Question 80

Match the term with its description:
a.adhesion
c.surface tension
b.cohesion
d.capillary action
Sticking together of like molecules