Title: Chemistry of Life
Course: Question Banks

Q: Which of the following is the fundamental unit of matter?
- the electron (Incorrect. An electron is a subparticle of the fundamental unit of matter.)
- the cell (Incorrect. A cell is the fundamental unit of life, not of matter.)
- the atom (Correct. The atom is the most basic unit of matter.)
A: the atom

Q: An atom’s________ are disregarded when calculating its mass.
- neutrons (Incorrect. Neutrons provide a vital contribution to the mass of an atom.)
- protons (Incorrect. Protons provide a vital contribution to the mass of an atom.)
- electrons (Correct. Electrons provide an insignificant amount of the mass of an atom and therefore are disregarded when calculating atomic mass.)
A: electrons

Q: Using the accompanying figure to answer the following question. Which letter indicates the neutrons of the atom?
- A (Incorrect. These particles are electrons.)
- C (Incorrect. These particles are protons.)
- D (Incorrect. Neutrons (B) and protons (C) together make up the nucleus of an atom.)
- B (Correct. These particles are neutrons.)
A: B

Q: Atoms are composed of ________ and ________.
- a nucleus; a membrane (Incorrect. Atoms do not have membranes.)
- a membrane; an electron shell (Correct. This is one component of an atom.)
- a nucleus; an electron shell (Correct. This is one component of an atom.)
A: a nucleus; an electron shell

Q: ________ devised the periodic table of elements.
- Mendel (Incorrect. Mendel is the father of genetics, whom you have not yet met.)
- Bohr (Incorrect. Bohr developed the early model of an atom in 1913.)
- Mendeleev (Correct. Mendeleev developed the periodic table of elements in 1869.)
A: Mendeleev

Q: Elements are displayed in order of ________ in the periodic table of elements.
- atomic mass (Incorrect. Atomic mass is not used to organize the periodic table.)
- electron mass (Incorrect. Electron mass is not used to organize the periodic table.)
- atomic number (Correct. The periodic table is structured by atomic number.)
A: atomic number

Q: The periodic table displays an element’s ________ and atomic number.
- neutron number (Incorrect. The periodic table does not specify neutron number.)
- electron number (Incorrect. The periodic table does not specify electron number.)
- atomic mass (Correct. The periodic table provides both atomic mass and atomic number.)
A: atomic mass

Q: Chemical reactivity in elements is controlled by ________.
- neutrons (Incorrect. Neutrons do not impact chemical reactivity.)
- protons (Incorrect. Protons are not involved in chemical reactivity.)
- electrons (Correct. It is the behavior of electrons that controls reactivity of an atom, and hence chemicals.)
A: electrons

Q: Potassium has an atomic number of 19. What is its electron configuration?
- Shells 1 and 2 are full, and shell 3 has nine electrons. (Incorrect. Shell 1 holds 2 electrons and all other shells follow the octet rule.)
- Shells 1, 2, and 3 are full and shell 4 has three electrons. (Incorrect. Shell 1 holds 2 electrons and all other shells follow the octet rule.)
- Shells 1, 2, and 3 are full, and shell 4 has one electron. (Correct. Shell 1 holds 2 electrons and all other shells follow the octet rule.)
A: Shells 1, 2, and 3 are full, and shell 4 has one electron.

Q: According to the ________, atoms want their outer electron shells to be filled.
- valence shell (Incorrect. The valence shell is simply the name of the outermost electron shell.)
- orbital rule (Incorrect. An orbital is the path an electron follows around an atom’s nucleus.)
- octet rule (Correct. The octet rule states that atoms are energetically more stable with their outer shell filled with electrons.)
A: octet rule

Q: Each carbon can bond with as many as ________ other atoms or molecules.
- two (Incorrect. Remember to consider how many electrons carbon has in its valence shell.)
- six (Incorrect. Remember to consider how many electrons carbon has in its valence shell.)
- four (Correct. Carbon has four electrons in its valence shell and will hence form four bonds to fill its outermost shell.)
A: four

Q: Which subshell always fills first?
- The 1p (Incorrect. The p subshell is filled after the s.)
- The 2s (Incorrect. The ‘1’ shell is filled before the ‘2’.)
- The 1s (Correct. The s subshell is filled before the p.)
A: The 1s

Q: Noble gases rarely form chemical bonds because ________.
- their inner electron shells are full (Incorrect. Inner electron shells do not impact chemical bond formation.)
- their second shell is full (Incorrect. All noble gases do not have a second electron shell.)
- their outermost electron shell is full (Correct. Noble gases rarely form chemical bonds because their outermost electron shell is full, and therefore energetically stable.)
A: their outermost electron shell is full

Q: In an ionic bond, the charge on the cation is ________.
- always negative (Incorrect. A cation is an ion with fewer electrons than protons, always giving it a positive charge.)
- either negative or positive (Incorrect. Cations are characterized by a single charge.)
- always positive (Correct. Cations are always positive.)
A: always positive

Q: Which of the following best explains the natural formation of ions?
- a filled outer electron shell and a large electronegativity differential (Incorrect. This describes a hydrogen bond, which you have yet to cover.)
- an unfilled outer electron shell and electron sharing (Incorrect. This describes the formation of a covalent bond, which you have yet to cover.)
- an unfilled outer electron shell and electron transfer (Correct. It is the transfer of electrons that creates the positive and negative charges associated with ions.)
A: an unfilled outer electron shell and electron transfer

Q: In an ionic bond, which element gains electrons?
- the metal (Incorrect. The metal loses electrons in an ionic bond.)
- the noble gas (Incorrect. Remember, noble gases are generally non-reactive.)
- the nonmetal (Correct. The nonmetal gains electrons in an ionic bond.)
A: the nonmetal

Q: Which of the following is a correct statement?
- Covalent bonds lead to molecules that are stable in air while ionic bonds do not. (Incorrect. No bond type is automatically more or less stable in air.)
- ​Covalent bonds only occur between atoms of similar electronegativities while ionic bonds only occur between atoms of differing electronegativities. (Incorrect. Electronegativities play a role in hydrogen bonds only.)
- Ionic bonds to do not share valence electrons while covalent bonds do. (Correct. Covalent bonds involve sharing of electrons.)
A: Ionic bonds to do not share valence electrons while covalent bonds do.

Q: How are double bonds formed?
- Double bonds form any time carbon is involved in a bond. (Incorrect. Carbon is not the only atom that will form double bonds, nor does it automatically form double bonds.)
- Double bonds form when p orbital electrons are shared. (Incorrect. Double bonds do not automatically involve the p orbital.)
- Double bonds form when two pairs of electrons are shared. (Correct. Sharing two pairs of electrons is what makes a bond “double.”)
A: Double bonds form when two pairs of electrons are shared.

Q: Select the bond that is most polar.
- N ≡ N (Incorrect. Because this bond involves only N, the electrons will be shared equally.)
- H – C (Incorrect. This will be a polar bond but the size differential between C and H is not the largest in the answer choices.)
- O – H (Correct. Because O is much larger than H, it will attract electrons more strongly.)
A: O – H

Q: Which type of bond represents a weak chemical bond?
- covalent bond (Incorrect. Covalent bonds are extremely strong because they involve shared electrons.)
- ionic bond (Incorrect. Ionic bonds are very strong.)
- hydrogen bond (Correct. Hydrogen bonds are weak chemical attractions based on differences in electronegativity.)
A: hydrogen bond

Q: Which type of bond enables many of the properties of water?
- polar covalent bond (Incorrect. Individual molecules of water are formed by polar covalent bonds between H and O but this is not what enables many of the properties of water.)
- nonpolar covalent bond (Incorrect. Individual molecules of water are formed by polar covalent bonds between H and O but this is not what enables many of the properties of water.)
- hydrogen bond (Correct. The weak hydrogen bonds between different molecules of water enable many of the properties of water.)
A: hydrogen bond

Q: When hydrogen is involved in a polar covalent bond, it has a ________.
- slight negative charge (Incorrect. Hydrogen is a small atom and is more likely to ‘lose’ its electron during a covalent sharing.)
- strong positive charge (Incorrect. Hydrogen only has a single electron so it cannot fully transfer it, which is required for a strong positive charge to form.)
- slight positive charge (Correct. Hydrogen is a small atom and is more likely to ‘lose’ its electron during a covalent sharing. This makes hydrogen slightly positive (less electronegative).)
A: slight positive charge

Q: Which functional group contains only hydrogen and oxygen?
- Carbonyl (Incorrect. A carbonyl group contains only carbon and oxygen.)
- Methyl (Incorrect. A methyl group contains only hydrogen and carbon.)
- Hydroxyl (Correct. A hydroxyl group contains only hydrogen and oxygen.)
A: Hydroxyl

Q: The ________ functional group has as simple structure and causes a molecule to be polar.
- carboxyl (Incorrect. A carboxyl functional group is acidic, not polar.)
- methyl (Incorrect. A methyl group is nonpolar.)
- hydroxyl (Correct. A hydroxyl group is a very simple, polar functional group.)
A: hydroxyl

Q: Molecules with a hydroxyl group are ________.
- hydrophobic (Incorrect. Molecules with hydroxyl groups are not hydrophobic.)
- charged (Incorrect. Molecules with hydroxyl groups are not charged.)
- hydrophilic (Correct. The hydroxyl group makes a molecule polar, which in turn makes it hydrophilic.)
A: hydrophilic

Q: The ________ functional group is considered acidic.
- amino (Incorrect. The amino group is basic.)
- methyl (Incorrect. The methyl group is nonpolar.)
- carboxyl (Correct. The carboxyl group is acidic.)
A: carboxyl

Q: The charged ________ group donates hydrogen ions to solutions.
- amino (Incorrect. The amino group does not donate hydrogen ions to solutions.)
- sulfhydryl (Incorrect. The sulfhydryl group does not donate hydrogen ions to solutions.)
- carboxyl (Correct. The carboxyl group donates hydrogen ions to solutions.)
A: carboxyl

Q: The only functional group that is based on a nitrogen atom is the ________ group.
- phosphate (Incorrect. The phosphate group contains phosphate.)
- carboxyl (Incorrect. The carboxyl group does not contain nitrogen.)
- amino (Correct. Only the amino group contains nitrogen.)
A: amino

Q: Which functional group is basic?
- phosphate (Incorrect. The phosphate group is acidic.)
- carboxyl (Incorrect. The carboxyl group is acidic.)
- amino (Correct. The amino group is basic.)
A: amino

Q: A ________ group, which is non-carbon based, is charged.
- hydroxyl (Incorrect. The hydroxyl group is polar, not charged.)
- sulfhydryl (Incorrect. The sulfhydryl group is polar, not charged.)
- phosphate (Correct. The phosphate group has no carbon and is charged.)
A: phosphate

Q: Which type of group is more complex than amino groups?
- hydroxyl group (Incorrect. The hydroxyl group is not more complex than the amino group.)
- sulfhydryl group (Incorrect. The sulfhydryl group is not more complex than the amino group.)
- phosphate group (Correct. The phosphate group has a more complex structure than the amino group.)
A: phosphate group

Q: The ________ is considered acidic because it donates hydrogen ions.
- carbonyl group (Incorrect. The carbonyl group is polar, not acidic.)
- amino group (Incorrect. The amino group is basic, not acidic.)
- phosphate group (Correct. The phosphate group is considered acidic.)
A: phosphate group

Q: A ________ group is based around a carbon bound to hydrogens and an organic molecule.
- carboxyl (Incorrect. The carboxyl molecule also contains oxygen.)
- carbonyl (Incorrect. The carbonyl molecule also contains oxygen.)
- methyl (Correct. The methyl group contains only carbon and hydrogen bound to an organic molecule.)
A: methyl

Q: The nonpolar methyl is a(n) ________ functional group.
- branched (Incorrect. The methyl group is not branched.)
- complex (Incorrect. The methyl group is not complex.)
- unbranched (Correct. The methyl group is unbranched.)
A: unbranched

Q: The presence of a ________ group makes a molecule hydrophobic.
- hydroxyl (Incorrect. The hydroxyl group makes a molecule polar, which means it will be hydrophilic.)
- sulfhydryl (Incorrect. The sulfhydryl group makes a molecule polar, which means it will be hydrophilic.)
- methyl (Correct. The methyl group is nonpolar, which makes the molecule hydrophobic.)
A: methyl

Q: The ________ functional group has a central carbon bound to an oxygen atom and two organic side molecules.
- sulfhydryl (Incorrect. The sulfhydryl group does not have two organic side molecules.)
- carboxyl (Incorrect. The carboxyl group does not have two organic side molecules.)
- carbonyl (Correct. The carbonyl group has a central carbon double bound to an oxygen atom and two organic side molecules.)
A: carbonyl

Q: A polar carbonyl functional group is the only functional group bound to ________ organic molecules.
- one (Incorrect. Most functional groups are bound to one organic molecule.)
- three (Incorrect. There is no functional group bound to three organic molecules.)
- two (Correct. The carbonyl group is the only functional group bound to two organic molecules.)
A: two

Q: A carbonyl functional group makes a molecule ________.
- hydrophobic (Incorrect. The carbonyl group does not make a molecule hydrophobic.)
- charged (Incorrect. The carbonyl group does not make a molecule charged.)
- hydrophilic (Correct. The carbonyl group makes a molecule polar, which makes it hydrophilic.)
A: hydrophilic

Q: Which of the following is a simple polar, branched functional group with no carbon?
- methyl group (Incorrect. The methyl group contains carbon.)
- amino group (Incorrect. The amino group makes a molecule basic, not polar.)
- sulfhydryl group (Correct. The sulfhydryl group is a simple polar, branched functional group based on sulfur, not carbon.)
A: sulfhydryl group

Q: Which of the following is more structurally complex than a hydroxyl group, but is not charged?
- amino group (Incorrect. The amino group is more structurally complex, but it is basic.)
- methyl group (Incorrect. The methyl group is simpler than a hydroxyl group since it has no branches.)
- sulfhydryl group (Correct. The sulfhydryl is branched and polar, but not charged.)
A: sulfhydryl group

Q: Which of the following would be more polar than a sulfhydryl group?
- an amino group (Incorrect. The amino group accepts H+ ions and makes the molecule basic (positively charged), not polar.)
- a phosphate group (Incorrect. The phosphate group releases H+ ions and makes the molecule acidic (negatively charged), not polar.)
- a hydroxyl group (Correct. Oxygen is more electronegative than sulfur; therefore, a hydroxyl group is more polar than a sulfhydryl group.)
A: a hydroxyl group

Q: When acids are added to a solution, the pH should ________.
- increase (Incorrect. Acids do not cause pH to increase.)
- stay the same (Incorrect. Acids will change the pH.)
- decrease (Correct. Acids cause pH to decrease.)
A: decrease

Q: ________ are substances that release hydrogen ions.
- Basic substances (Incorrect. Basic solutions do not release hydrogen ions.)
- Neutral substances (Incorrect: Neutral solutions do not release hydrogen ions.)
- Acidic substances (Correct. The definition of an acid is a substance that releases hydrogen ions.)
A: Acidic substances

Q: Blood maintains a ________ pH.
- acidic (Incorrect. Blood is not acidic.)
- basic (Incorrect. Blood is not basic.)
- near-neutral (Correct. Blood is near-neutral to avoid damaging substances transported in it.)
A: near-neutral

Q: Using a pH meter, you find the pH of an unknown solution to be 8.0. How would you describe this solution?
- weakly acidic (Incorrect. A pH above 7 is not acidic.)
- strongly basic (Incorrect. Any pH near 7 is not “strong”.)
- weakly basic (Correct. This pH is above 7 but not by much, making it weakly basic.)
A: weakly basic

Q: A landscaper wants to plant shrubs that require a soil pH of 7.0 near some evergreen trees. The soil in this location is a pH of 6.0. What can he conclude and what course of action will address the problem?
- The soil has a tenth of the H+ concentration he desires, so he should add some acetic acid to the soil. (Incorrect. The lower the pH value, the more H+ present.)
- The soil has ten times the H+ concentration he desires, so he should add some acetic acid to the soil. (Incorrect. To raise the pH one must add alkaline material, not acidic.)
- The soil has ten times the H+ concentration he desires, so he should add an alkaline material to the soil. (Correct. The pH scale is a log scale (times 10 for every number) and to raise the pH one must add alkaline material.)
A: The soil has ten times the H+ concentration he desires, so he should add an alkaline material to the soil.

Q: ________ of hydrogen ions result in a high pH.
- Mid-range levels (Incorrect. Mid-range concentration of H+ concentration would not provide high pH values.)
- High levels (Incorrect. The higher the H+ concentration, the lower the pH value.)
- Low levels (Correct. The lower the H+ concentration, the higher the pH value.)
A: Low levels

Q: Buffers function by ________.
- absorbing excess hydrogen and releasing hydroxide ions (Incorrect. This would result in a more basic solution.)
- releasing hydrogen and absorbing excess hydroxide ions (Incorrect. This would result in a more acidic solution.)
- absorbing excess hydrogen or hydroxide ions (Correct. Buffers work to minimize changes in either ion’s concentration.)
A: absorbing excess hydrogen or hydroxide ions

Q: ________ in the body affect blood pH by creating bicarbonate when the pH needs to be lowered.
- Acids (Incorrect. Acids do not create bicarbonate.)
- Bases (Incorrect. Bases do not work to lower pH.)
- Buffers (Correct. Buffers will work to stabilize the pH in whatever direction is needed.)
A: Buffers

Q: A common household example of a buffer is ________.
- Bleach (Incorrect. This is a base.)
- lemon juice (Incorrect. This is an acid.)
- antacid (Correct. This is a buffer designed to modulate stomach acid pH in particular.)
A: antacid

Q: Ultimately, excess ________ build up in the body is prevented by the exhalation of carbon dioxide.
- bicarbonate (Incorrect. Bicarbonate is used as a buffer in the body, and is not removed by exhalation of carbon dioxide.)
- hydrogen atoms (Incorrect. Hydrogen atoms are neutral and have no impact on pH, nor will they build up in the body.)
- hydrogen ions (Correct. This prevents build up of carbonic acid specifically.)
A: hydrogen ions

Q: Which symbol separates the reactants from products in a reaction and means "to yield"?
- (s) (Incorrect. This symbol is not used when indicating chemical reactions.)
- + (Incorrect. This indicates reactants that combine.)
- → (Correct. This indicates the reactants “ yield” the product(s) in a chemical reaction.)
A: →

Q: In the following reaction, which chemical is the product?
- 2H (Incorrect. This is a reactant.)
- O (Incorrect. This is a reactant.)
- H_2O (Correct. This is the product.)
A: H_2O

Q: The substances involved in the ________ of a chemical reaction are the reactants.
- end (Incorrect. The products are present at the end.)
- middle (Incorrect. The ‘middle’ chemicals are known as intermediaries.)
- beginning (Correct. The reactants are present when a chemical reaction begins.)
A: beginning

Q: Reversible reactions can proceed in ________ direction.
- only one (Incorrect. This would be an irreversible reactions.)
- neither (Incorrect. No reaction would occur without progress one way or another.)
- either (Correct. Reversible reactions move either way, to products or to reactants.)
A: either

Q: Catabolic reactions ________ energy.
- require (Incorrect. This would be an anabolic reaction.)
- consume (Incorrect. Consume typically means "to use up", and catabolic reactions give/create energy rather than using it.)
- release (Correct. Catabolic reactions release energy as they breakdown molecules.)
A: release

Q: Carbonic acid forming into CO_2 and H_2O is a ________ reaction.
- synthesizing (Incorrect. This term does not describe the catabolic breakdown of carbonic acid.)
- anabolic (Incorrect. Anabolic reactions build larger molecules by joining together smaller ones.)
- catabolic (Correct. Catabolic reactions break larger molecules into several smaller ones.)
A: catabolic

Q: Which of the reactions below is an anabolic one?
- Digesting a sugar molecule (Incorrect. This would be a catabolic reaction.)
- Burning a piece of wood (Incorrect. This would be a catabolic reaction, specifically a combustion reaction.)
- Synthesizing DNA (Correct. Anabolic reactions build larger molecules by joining together smaller ones.)
A: Synthesizing DNA

Q: A(n) ________ speeds up a reaction, while largely remaining unchanged itself.
- protein (Incorrect. Not all proteins play a role in reaction rates.)
- amino acid (Incorrect. Amino acids are simply protein building blocks.)
- enzyme (Correct. Enzymes are specialized proteins that speed up reactions without themselves being consumed.)
A: enzyme

Q: Use the accompanying figure to answer the following question. As shown on this graph, which letter indicates the enzyme-mediated reaction?
- A (Incorrect. This is the stand-alone reaction.)
- C (Incorrect. This is the activation energy required for the stand-alone reaction.)
- D (Incorrect. This is the energy released by the reaction, regardless of enzyme activity.)
- B (Correct. This is the enzyme-mediated reaction, which requires much less activation energy.)
A: B

Q: Enzymes are typically react with ________.
- any substrate they encounter (Incorrect. Enzymes are not generalists.)
- a handful of substrates (usally around ten) (Incorrect. Even if an enzyme has more than one substrate, it will not have many.)
- one specific substrate (Correct. Most enzymes are specific to only a single substrate.)
A: one specific substrate

Q: Identify the open system from the list below.
- A vacuum sealed bag (Incorrect. A vacuum sealed bag does not exchange materials outside itself.)
- A closed bottle (Incorrect. A closed bottle does not exchange materials outside itself.)
- A dishwasher (Correct. A dishwasher must exchange water with the ‘outside’.)
A: A dishwasher

Q: Open and closed systems differ in the way energy is ________ the system.
- used outside (Incorrect. Something occurring purely outside the system does not define open vs. closed systems.)
- transferred within (Incorrect. Something occurring purely within the system does not define open vs. closed systems.)
- transferred outside (Correct. Energy exchange outside the system is what distinguishes open vs. closed systems.)
A: transferred outside

Q: A multicellular organism is a(n) ________ system because ________.
- open; it is contained within a cell membrane (Incorrect. The presence of an outer barrier does not define a system as opened or closed.)
- closed; it is contained within a cell membrane (Incorrect. The presence of an outer barrier does not define a system as opened or closed.)
- closed; it exchanges energy with its surroundings (Incorrect. A closed system does not exchange energy with its surroundings.)
- open; it exchanges energy with its surroundings (Correct. An open system exchanges energy with its surroundings.)
A: open; it exchanges energy with its surroundings

Q: According to the First Law of Thermodynamics, ________.
- the total amount of energy in the universe is gradually decreasing (Incorrect. This is not the First Law of Thermodynamics.)
- the energy in the universe is in a constant state of flux (Incorrect. This is not the First Law of Thermodynamics.)
- the total amount of energy in the universe is constant (Correct. This is the First Law of Thermodynamics.)
A: the total amount of energy in the universe is constant

Q: “Burning off” excess weight from Christmas cookies is an example of ________.
- the second law of thermodynamics (Incorrect. The Second Law of Thermodynamics involves increasing randomness in a system.)
- the destruction of energy (Incorrect. Energy cannot be destroyed, even when ‘burned’.)
- the first law of thermodynamics (Correct. Energy is neither created nor destroyed here: it is stored in the body and then used to power muscles during exercise.)
A: the first law of thermodynamics

Q: The First Law of Thermodynamics addresses ________.
- the usefulness of an energy resource such as oil (Incorrect. This actually relates to energy efficiency.)
- black holes destroying all the light around them (Incorrect. The First Law says energy is neither created nor destroyed.)
- conversion of energy to different forms (Correct. The First Law says energy is neither created nor destroyed.)
A: conversion of energy to different forms

Q: Entropy is ________.
- a measure of the energy gained by a system (Incorrect. This is not entropy.)
- a measure of the order in a system (Incorrect. This is not entropy.)
- a measure of the disorder in a system (Correct. Entropy measures disorder.)
A: a measure of the disorder in a system

Q: According to the Second Law of Thermodynamics, the randomness of the universe ________.
- is constantly decreasing (Incorrect. This is not the Second Law of Thermodynamics.)
- is constant (Incorrect. This is not the Second Law of Thermodynamics.)
- is constantly increasing (Correct. This is the Second Law of Thermodynamics.)
A: is constantly increasing

Q: According to ________, energy is constantly required to keep entropy low.
- the Zeroth Law of Thermodynamics (Incorrect. There is no such law in physics.)
- the First Law of Thermodynamics (Incorrect. The First Law says energy is neither created nor destroyed.)
- the Second Law of Thermodynamics (Correct. Since the Second Law tells disorder constantly increases, it also tells us energy must constantly be used to keep entropy (disorder) low.)
A: the Second Law of Thermodynamics