Chemistry MC: November 2018

Archive for November 2018

T/F, the two monolayers have different lipid and protein composition

Answer: True

T/F, Membranes are symmetric, homogeneous structures

Answer: False; Membranes are asymmetric, heterogeneous structures

Which terminal are Glycosyl Phosphatidylinositol proteins always bound to?

Answer: C-terminal

Which type of lipid anchored protein is the most elaborate?

Answer: Glycosyl Phosphatidylinositol

T/F Thioester and Acyl anchors have a broader range of lipids and proteins to bind to

Answer: True

Name the the lipid anchor specifics for Amide-Linked Myristoyl

Answer:

The lipid anchor is always myristic acid
It is always N-terminal
It is always a Gly residue that links

What does it mean for the lipids and proteins of the membrane to exhibit transverse symmetry?

Answer: The extracellular and cytoplasmic ends of transmembrane proteins can be vastly different from each other

What does it mean for the lipids and proteins of the membrane to exhibit lateral heterogeneity?

Answer: Clusters of lipids/proteins can occur in the membrane, they don't have to be uniformly distributed

T/F, Lipid-anchored membrane proteins can be both covalently linked and reversibly bound

Answer: True

Define Lipid-Anchored Membrane Proteins:

Answer: Proteins covalently linked to lipids embedded in the membrane

Name 4 types of lipid-anchored membrane proteins:

Answer: Amide Linked Myristoyl, Thioester linked fatty acid, Thioether linked prenyl, and glycosyl phosphatidylinositol

Describe the inside and outside of Wza's structure

Answer: The outside has a nonpolar surface to contact the interior of the lipid bilayer, and the inside of the pore has a hydrophilic inner surface to contact the H2O-filled pore

Describe the structure of Wza:

Answer: Octameric alpha-helical barrel structure traverses the membrane to create an amphiphilic pore.

T/F Alpha helices cannot form transmembrane "barrels"

Answer: False, alpha helices can form transmembrane barrel structures

Why are beta sheets so commonly found in transmembrane proteins?

Answer: They only require 9-11 residues to traverse the lipid bilayer (as opposed to 21-25 when traversing with an alpha helix). Therefore a given amount of genetic material can make more transmembrane proteins when they are in a beta sheet configuration.

Where are porins found?

Answer: In G- bacteria and the mitochondrial outer membrane

Define Porins:

Answer: Pore-forming proteins (30-50 kD) embedded in the membrane.

Name 5 other structural changes that can occur in a transmembrane protein:

Answer: Tilted helices, Reentrant loops, Regions of non helical peptide, Interrupted helices, Barrel configurations to span the membrane

Explain the significance of the "Positive Inside" rule:

Answer: Positively charged residues are usually located on the cytoplasmic face of the lipid bilayer

Which type of amino acids are commonly found in the lipid tail interior of the lipid bilayer?

Answer: Hydrophobic

Which specific protein residues are most commonly found at the interface between the lipid and water?

Answer: Trp, His, Tyr

Where are charged and polar residues of a protein found in relation to the cell membrane?

Answer: Charged and polar residues of a protein are found at the lipid-H2O interface

Define Hydropathy Index:

Answer: An average of the hydrophobicities for each segment of the protein

On a hydropathy plot, which sign indicates hydrophobic (transmembrane) segments?

Answer: Positive sign indicates hydrophobic (transmembrane segments). Negative sign indicates hydrophilic (polar) segments).

What are the two quantities that protein topology is based on?

Answer: Hydropathy plot and assignment of hydrophobicity values to each AA in the sequence

What is the name of the light-driven proton pump found in purple patches of Halobacterium Halobium?

Answer: Rhodopsin

T/F, Rhodopsin is made of 7 transmembrane helical segments with short loops connecting said helices

Answer: True

Name 5 ways a peripheral protein will associate with the membrane:

Answer: May form ionic interactions, H-Bonds, amphipathic alpha helix, hydrophobic loop with membrane, or association with integral protein.

Which generally has more transmembrane segments, transport or membrane proteins?

Answer: Transport proteins usually have more transmembrane segments (6-12). Membrane proteins usually have 2-12 transmembrane segments.

How many transmembrane segments does glycophorin have?

Answer: 1

T/F, Peripheral membrane proteins are dissociated from the membrane by denaturation.

Answer: False. Peripheral membrane proteins are dissociated using mild detergents or high salt concentration

Define Peripheral Membrane Protein:

Answer: Protein which is weakly bound to the membrane.

What are the extracellular components of glycophorin which specify ABO/MN blood type determinants?

Answer: Oligosaccharides

T/F Glycophorin has three transmembrane segments, globular domains on both ends.

Answer: False; Glycophorin has a single transmembrane segment with globular domains on both ends of the protein

What do most integral proteins have in common?

Answer: The portions of the protein in contact with the non polar core of the lipid bilayer are dominated by alpha helices/beta sheets to stabilize the NH and C=O moieties through Hbond stabilization

Give two examples of Integral Membrane Proteins:

Answer: Glycophorin and Bacteriorhodopsin

Define "Integral Membrane Protein"

Answer: Protein which is strongly embedded in the bilayer. Can only be removed from the membrane by denaturing it. Often transmembrane, but not necessarily.

Name the 3 classes of membrane proteins:

Answer: Integral, Peripheral, and Lipid-Anchored

Where is the most motion and greatest entropy featured in the lipid bilayer?

Answer: Mid-membrane, where the lipid hydrocarbon tails are located

T/F Portion of the lipid chain nearest the membrane surface lies parallel to the membrane plane

Answer: False; Portion of the lipid chain nearest the membrane surface lies perpendicular to the membrane plane

Describe two tenets of the Fluid Mosaic Model:

Answer: Phospholipid bilayer is a fluid matrix/2D solvent. Lipids and proteins within the mosaic can undergo lateral and rotational movement

What happens to a micelle when it is placed in a nonpolar solvent?

Answer: It will turn inside out; The polar heads will be in the center of the sphere, and the hydrocarbon tails will be facing out

Describe a lipid monolayer on the surface of a polar solvent:

Answer: Lipid molecules arrange themselves on the surface of the solvent with their polar head groups touching the solvent and with their lipophilic tails in the air

Name the most common membrane protein:

Answer: Phosphatidylcholine (1,2-diacylglycerol with esterified carbon on C3 featuring attached choline head group)

T/F Membranes which carry out many enzyme catalyzed reactions and transport activities must be lipid rich

Answer: False; Membranes which carry out many enzyme catalyzed reactions and transport activities must be protein rich

T/F Depending on the membrane, it can contain 50%-80% protein

Answer: False; It can contain 15%-80% protein

Give two reasons why Lipids form membranes:

Answer: Hydrophobic effect promotes self-association of lipids in water. Water prefers polar associations, would rather associate with itself.

What are the reagents needed for Lithium Aluminum Hydride reduction of carboxylic acids? What is the overall result?

Answer:

1. LiAlH4, Diethyl Ether

2. H2O; Carboxylic acid group is changed into an alcohol group

Name 3 reactions of carboxylic acids presented in the chapter:

Answer: Formation of acyl chlorides, Lithium Aluminum Hydride Reduction, Fischer esterification.

Name three reactions given by the chapter which you can use to synthesize carboxylic acids without adding a carbon to the parent chain:

Answer: Side-chain oxidation of alkylbenzenes, Oxidation of primary alcohols, Oxidation of aldehydes. All three only need the reagent KMnO4 or K2Cr2O7 followed by acid workup(H2SO4)

How do you decarboxylate malonic acid?

Answer: Heat it above its melting point. CO2 just disappears from one of the carboxylic acid groups, and the rest of the molecule looks the same.

How are lactones named?

Answer: Replace -oic with -olide, and identify its oxygenated carbon by number

What are "lactones"?

Answer: Intramolecular esters. Formed by hydoxy acids (compounds containing both a hydroxyl and a carboxylic acid function)

What is the skeleton reaction of acid-catalyzed esterification?

Answer: Carboxylic acid plus alcohol goes to ester plus water

What are the products when carboxylic acid is reacted with 1. LiAlH4, diethyl ether 2, H2O?

Answer: Primary alcohol

What is(are) the products when carboxylic acid is reacted with thionyl chloride?

Answer: Acyl chloride, Sulfur dioxide, and hydrogen chloride

When acid-catalyzed esterification is carried out, where does the hydroxyl oxygen come from?

Answer: The alcohol

Given an alkyl chloride, how would you carboxylate it and add to the chain by one? (cyanide method)

Answer: 1. NaCN, DMSO 2. H2O, H2SO4, heat

Given an alkyl chloride, what are the three reagents (in order) needed to carboxylate the compound while adding another carbon to the chain? (carbon dioxide method)

Answer: 1. Mg, diethyl ether 2. CO2 3. H3O+

Name two ways to prepare carboxylic acids while extending the parent chain by a carbon:

Answer: Carboxylation of Grignard reagents; Preparation and hydrolysis of nitriles

How do you oxidize aldehydes?

Answer: KMnO4 or chromic acid

How do you oxidize a primary alcohol?

Answer: KMnO4 or chromic acid (K2Cr2O7

How do you convert a primary or secondary alkyl side chain on an aromatic ring to a carboxyl group?

Answer: Reaction with KMnO4 or Chromic acid

What is the reaction most used for the commercial production of acetic acid?

Answer: Methanol + Carbon dioxide -> Acetic acid

How does bicarbonate compare in acidity to carboxylic acids, water, and alcohol?

Answer: Bicarbonate is a weaker acid than carboxylic acid, but a stronger acid than water and alcohol

What happens when an amphiphilic substance is placed in water?

Answer: It forms a colloidal dispersion of micelles (aggregates with the carboxylate groups on the outside and the hydrocarbon chains on the inside).

What is the definition of an amphiphilic substance?

Answer: Amphiphilic substances have both hydrophilic and lipophilic groups within them

Which parts of sodium stearate are hydrophilic, and which parts are lipophilic?

Answer: The carboxylate group is hydrophilic, The hydrocarbon chain is lipophilic

How do you name the carboxylic acid salts?

Answer: Specify the metal ion. Add the name of the acid modified by turning the -ic suffix into -ate

What happens to carboxylic acids in the presence of strong bases such as NaOH?

Answer: Carboxylic acids are neutralized quickly to their carboxylate anion salts and water.

In substituted benzoic acids, the largest effects on acidity occur when the electron-withdrawing substituents are in which location?

Answer: Ortho

Does carbon become more or less electron-withdrawing as its s-character increases?

Answer: Carbon becomes more electron-withdrawing as its s-character increases.

Which is a stronger acid, acetic acid or benzoic acid?

Answer: Benzoic acid; Its carboxyl group is attached to an sp2-hybridized carbon and therefore ionizes to a greater extent than one attached to an sp3-hybridized carbon

Define the "field effect":

Answer: An electronegative substituent makes its presence known by polarizing the solvent.

What does the effect of an electronegative substituent have on an ionizable hydrogen?

Answer: Increases the hydrogen's acidity by stabilizing the anion

What is the Henderson-Hasselbalch equation, and how does it relate to our study of carboxylic acids?

Answer: pH=pKa + log[conjugate base]/[conjugate acid]. We can use it to find out which of the two are prevalent in a solution, the neutral carboxylic acid molecule or the charged carboxylate ion

Why are carboxylic acids so much more acidic than their alcohol analogs?

Answer:

1. The carbonyl group is electron-withdrawing. It stabilizes the acetate anion, contributing to the carboxylic acid's acidity.

2. The carbonyl group also allows for electron delocalization, with resonance between the two oxygens, again stabilizing the acetate anion

True or false, carboxylic acids are the most acidic class of compounds that contain only carbon, hydrogen, and oxygen.

Answer: True

True or false, carboxylic acids are much stronger acids than water and alcohols.

Answer: True

Describe the hydrogen bonding unique between carboxylic acids:

Answer: Hydrogen of Carboxylic A's Hydroxyl attaches to Carboxylic B's Carbonyl. Carboxylic B's hydroxyl hydrogen attaches to Carboxylic A's carbonyl group.

In formic acid, which is the most electron-rich site, and which is the most electron-poor site?

Answer: Carbonyl oxygen is the most electron-rich, OH hydrogen is the most electron-poor

What are the IUPAC names for the dicarboxylic acids?

Answer: Ethanedioic, Propanedioic, Butanedioic, Pentanedioic, Hexanedioic, Heptanedioic, Octanedioic, Nonanedioic, Decanedioic

What are the common names for the dicarboxylic acids?

Answer: Oxalic, Malonic, Succinic, Glutaric, Adipic, Pimelic, Subaric, Azelaic, Sebacic

What are the IUPAC names for the carboxylic acids, in order?

Answer: Methanoic, Ethanoic, Propanoic, Butanoic, Pentanoic, Hexanoic, Octanoic, Decanoic, Dodecanoic, Tetradecanoic, Hexadecanoic, Octadecanoic

What are the common names for the carboxylic acids, in order of increasing number of carbons?

Answer: Formic, Acetic, Pyruvic, Butyric, Valeric, Caproic, Caprylic, Capric, Lauric, Myristic, Palmitic, Stearic

Which of the following will react with Br2 but not with I2?

A OH−
B SO32−
C Fe2+
D Mn2+

Answer: C Fe2+

Which of the following statements regarding a chemical reaction at equilibrium is always correct?

A The rates of the forward and reverse reactions are equal.
B The concentration of reactants and products are equal.
C The forward and reverse reactions have stopped.
D The addition of a catalyst changes the position of the equilibrium.

Answer: A The rates of the forward and reverse reactions are equal.

Which of the following is an isomer of 2,2-dimethylpentan-1-ol?

A CH3CH2CH2CH(CH3)CH2OH
B (CH3)3CCH(CH3)CH2OH
C CH3CH2CH2CH2CH2CH2CH2CH2OH
D (CH3)2CHC(CH3)2CH2CH2OH

Answer: B (CH3)3CCH(CH3)CH2OH

Which line in the table correctly describes the reaction of a ketone with bromine solution and with acidified potassium dichromate solution?

Br solution - acidified potassium dichromate solution

A no reaction no reaction
B no reaction orange to green
C decolourises orange to green
D decolourises no reaction

Answer: D decolourises no reaction

Which of the following statements is correct for ketones?

A They are formed by oxidation of tertiary alcohols.
B They contain a carboxyl group.
C They will not react with Fehling's solution.

Answer: C They will not react with Fehling's solution.

Which of the reaction responsible for browning of a cut fruit?

Answer: Oxidation

When an oil is hydrolysed, what molecule is always produced?

Answer: Glycerol (C3 H5 OH3)

Oils contain carbon to carbon double bonds which can undergo addition reactions with iodine. The iodine number of an oil is the mass of iodine in grams that will react with 100 g of oil. Which line in the table shows the oil that is likely to have the lowest melting point?

Oil Iodine number
A Corn 123
B Linseed 179
C Olive 81
D Soya 130

Answer: B Linseed 179

Which of the following mixtures will form when NaOH(aq) is added to a mixture of propanol and ethanoic acid?

A Propanol and sodium ethanoate
B Ethanoic acid and sodium propanoate
C Sodium hydroxide and propyl ethanoate
D Sodium hydroxide and ethyl propanoate

Answer: A Propanol and sodium ethanoate

Oil molecules are more likely to react with oxygen in the air than fat molecules. During the reaction the oil molecules

A are reduced
B become rancid
C are hydrolysed
D become unsaturated.

Answer: B become rancid

Which of the following is not an example of a van der Waals' force?

A Covalent bond
B Hydrogen bond
C London dispersion force
D Permanent dipole - permanent dipole attraction

Answer: A Covalent bond

Which of the following atoms has least attraction for bonding electrons?

A Carbon
B Nitrogen
C Phosphorus
D Silicon

Answer: D Silicon

Which of the following equations represents the first ionisation energy of fluorine?

A F −(g) → F(g) + e−
B F −(g) → 1/2 F2(g) + e−
C F(g) → F +(g) + e−
D 1/2 F2(g) → F +(g) + e−

Answer: C F(g) → F+(g) + e−

The elements nitrogen, oxygen, fluorine and neon

A can form negative ions
B are made up of diatomic molecules
C have single bonds between the atoms
D are gases at room temperature.

Answer: D are gases at room temperature.

Between which two elements is the difference in metallic character the greatest?

A) Rb and O
B) O and I
C) Rb and I
D) Li and O
E) Li and Rb

Answer: A

The list that correctly indicates the order of metallic character is __________.

A) B > N > C
B) F > Cl > S
C) Si > P > S
D) P > S > Se
E) Na > K > Rb

Answer: C

Of the elements below, __________ is the most metallic.

A) Na
B) Mg
C) Al
D) K
E) Ar

Answer: D

Which of the following correctly represents the second ionization of calcium? [*]

A) Ca(g) à Ca+ (g) + e-
B) Ca+(g) à Ca2+ (g) + e-
C) Ca-(g) + e- à Ca2- (g)
D) Ca+(g) + e- à Ca2+ (g)
E) Ca+(g) + e-à Ca (g)

Answer: B

Which equation correctly represents the first ionization of Barium? [*]

A) Ba(g) à Ba+ (g) + e-
B) Ba(g) à Ba- (g) + e-
C) Ba(g) + e- à Ba- (g)
D) Ba-(g) à Ba (g) + e-
E) Ba+(g) + e- à Ba (g)

Answer: A

Which of the following correctly represents the second ionization of phosphorus?

A) P+(g) + e-à P2+ (g)
B) P(g) à P+ (g) + e-
C) P-(g) + e-à P2- (g)
D) P+(g) à P2+ (g) +e-
E) P+(g) + e-à P (g)

Answer: D

Which equation correctly represents the first ionization of phosphorus?

A) P(g) +e- à P-(g)
B) P(g) à P-(g)+ e-
C) P(g) à P+(g) + e-
D) P-(g) à P(g) + e-
E) P+(g) +e- à P(g)

Answer: C

Which of the following correctly represents the second ionization of aluminum? [*]

A) Al+ (g) + e- à Al(g)
B) Al (g) à Al+(g) +e-
C) Al+ (g) à Al2+(g) + e-
D) Al+ (g) +e- à Al2+(g)
E) Al+ (g) à Al2+(g) +e-

Answer: C

Which equation correctly represents the first ionization of aluminum? [*]

A) Al- (g) à Al(g) +e-
B) Al (g) à Al-(g) +e-
C) Al (g) + e-à Al-(g)
D) Al (g) à Al +(g) +e-
E) Al+ (g) +e- à Al(g)

Answer: D

________ have the lowest first ionization energies of the groups listed.

A) Alkali metals
B) Transition metals
C) Halogens
D) Alkaline Earth metals
E) Noble gases

Answer: A

Of the elements below, __________ has the largest first ionization energy.

A) Li
B) K
C) Na
D) H
E) Rb

Answer: D

Of the following elements, which has the largest first ionization energy?

A) B
B) N
C) P
D) Si
E) C

Answer: B

Of the following elements, which has the largest first ionization energy?

A) Se
B) As
C) S
D) Sb
E) Ge

Answer: C

Of the following elements, which has the largest first ionization energy?

A) K
B) Rb
C) Sr
D) Ca
E) Ba

Answer: D

Of the following elements, which has the largest first ionization energy?

A) Na
B) Al
C) Se
D) Cl
E) Br

Answer: D

Of the following atoms, which has the largest first ionization energy?

A) Br
B) O
C) C
D) P
E) I

Answer: B

Of the choices below, which gives the order for first ionization energies?

A) Cl > S > Al > Ar > Si
B) Ar > Cl > S > Si > Al
C) Al > Si > S > Cl > Ar
D) Cl > S > Al > Si > Ar
E) S > Si > Cl > Al > Ar

Answer: B

The first ionization energies of the elements as you go from left to right across a period of the periodic table, and as you go from the bottom to the top of a group in the table.

A) increase, increase
B) increase, decrease
C) decrease, increase
D) decrease, decrease
E) are completely unpredictable

Answer: A

In general, as you go across a period in the periodic table from left to right:

(1) the atomic radius __________;
(2) the electronegativity __________; and
(3) the first ionization energy __________.

A) decreases, decreases, increases
B) increases, increases, decreases
C) increases, increases, increases
D) decreases, increases, increases
E) decreases, increases, decreases

Answer: D

Which of the elements below has the largest electronegativity?

A) Si
B) Mg
C) P
D) S
E) Na

Answer: D

Of the atoms below, __________ is the least electronegative.

A) Rb
B) F
C) Si
D) Cl
E) Ca

Answer: A

Of the atoms below, __________ is the most electronegative.

A) Si
B) Cl
C) Rb
D) Ca
E) S

Answer: B

Of the atoms below, __________ is the most electronegative.

A) Br
B) O
C) Cl
D) N
E) F

Answer: E

Electronegativity from left to right within a period and from top to bottom within a group.

A) decreases, increases
B) increases, increases
C) increases, decreases
D) stays the same, increases
E) increases, stays the same

Answer: C

The ability of an atom in a molecule to attract electrons is best quantified by the __________.

A) paramagnetism
B) diamagnetism
C) electronegativity
D) first ionization potential
E) electron change-to-mass ratio

Answer: C

is isoelectronic with argon and __ is isoelectronic with neon.

A) Cl - , F -
B) Cl - , Cl +
C) F +, F-
D) Ne-, Kr+
E) Ne-, Ar+

Answer: A

Which isoelectronic series is correctly arranged in order of increasing radius?

A) K + < Ca2+ < Ar < Cl -
B) Cl - < Ar < K + < Ca2+
C) Ca2+ < Ar < K + < Cl -
D) Ca2+ < K + < Ar < Cl -
E) Ca2+ < K + < Cl - < Ar

Answer: D

Which of the following is an isoelectronic series? [*]

A) B5-, Sr4-, As3-, Te2-
B) F -, Cl -, Br -, I -
C) S, Cl, Ar, K
D) Si2-, P2-, S2-, Cl2-
E) O2-, F -, Ne, Na +

Answer: D

Of the following species, __________ has the largest radius.

A) Rb +
B) Sr 2+
C) Br -
D) Kr
E) Ar

Answer: E

Sodium is much more apt to exist as a positive ion than is chlorine. This is because __________.

A) chlorine is a gas and sodium is a solid
B) chlorine has a greater electron affinity than sodium does
C) chlorine is bigger than sodium
D) chlorine has a greater ionization energy than sodium does
E) chlorine is more metallic than sodium

Answer: C

Chlorine is much more apt to exist as an negative ion than is sodium. This is because __________.

A) chlorine is bigger than sodium
B) chlorine has a greater ionization energy than sodium does
C) chlorine has a greater electronegativity than sodium does
D) chlorine is a gas and sodium is a solid
E) chlorine is more metallic than sodium

Answer: D

The most common sulfur ion has a charge of __________.

A) 2-
B) 1-
C) 4+
D) 6+
E) Sulfur does not form ions.

Answer: C

The ion with the smallest diameter is __________.

A) Br -
B) Cl -
C) I -
D) F -
E) O2-

Answer: A

Which ion below has the largest radius?

A) Cl -
B) K +
C) Br -
D) F -
E) Na +

Answer: D

Which of the following correctly lists the five atoms in order of increasing size (smallest to largest)?

A) O < F < S < Mg < Ba
B) F < O < S < Mg < Ba
C) F < O < S < Ba < Mg
D) O < F < S < Ba < Mg
E) F < S < O < Mg < Ba

Answer: C

In which of the following atoms is the 3s orbital closest to the nucleus?

A) Br
B) Cl
C) At
D) I
E) They are the same distance in all of these atoms.

Answer: B

Which of the following correctly lists the five atoms in order of increasing size (smallest to largest)?

A) F < K < Ge < Br < Rb
B) F < Ge < Br < K < Rb
C) F < K < Br < Ge < Rb
D) F < Br < Ge < K < Rb
E) F < Br < Ge < Rb < K

Answer: C

In which of the following atoms is the 2s orbital closest to the nucleus?

A) S
B) Cl
C) P
D) Si
E) They are the same distance in all of these atoms.

Answer: D

Which one of the following elements has the largest atomic radius?

A) O
B) F
C) Al
D) P
E) B

Answer: B

Which one of the following elements has the largest atomic radius?

A) Se
B) As
C) S
D) Sb
E) Te

Answer: C

Which one of the following atoms has the largest radius?

A) I
B) Co
C) Ba
D) Sr
E) Ca

Answer: D

Which one of the following has the smallest radius?

A) Na
B) Cl
C) P
D) Br
E) K

Answer: C

Which one of the following atoms has the largest radius?

A) Sr
B) Ca
C) K
D) Rb
E) Na

Answer: B

Which one of the following atoms has the largest radius?

A) O
B) F
C) S
D) Cl
E) Ne

Answer: D

The atomic radius of main-group elements generally increases down a group because ________.

A) effective nuclear charge increases down a group
B) effective nuclear charge decreases down a group
C) effective nuclear charge zigzags down a group
D) the principal quantum number of the valence orbitals increases
E) both effective nuclear charge increases down a group and the principal quantum number of the valence orbitals increases

Answer: C

Atomic radius generally increases as we move __________.

A) down a group and from right to left across a period
B) up a group and from left to right across a period
C) down a group and from left to right across a period
D) up a group and from right to left across a period
E) down a group; the period position has no effect

Answer: D

Elements Z and X are compared. Element Z is larger than Element X. Based on this you could say:

A) Element Z is further to the left side of the periodic table
B) Element X is closer to the top of the periodic table
C) Element Z and X are probably in the same group
D) A and/or B
E) B and/or C

Answer: A