Chapter 7: Periodic Properties of Elements

Consider the following electron configurations to answer the questions that follow: (i) 1s22s22p63s1 (ii) 1s22s22p63s2 (iii) 1s22s22p63s23p4 (iv) 1s22s22p63s23p4 (v) 1s22s22p63s23p5 The electron configuration belonging to the atom with the highest second ionization energy is __________. (ii) (iv) (v) (i) (iii)

(i)

Consider the following electron configurations to answer the questions that follow: (i) [Kr]5s1 (ii) [Ne]3s23p5 (iii) [Ar]4s23d104p4 (iv) [Ne]3s23p6 (v) [Ar]4s1 The electron configurations of the two atoms that form isoelectronic ions are __________. (iii) and (iv) (i) and (iii) (i) and (v) (ii) and (v) (ii) and (iii)

(ii) and (v)

Use bond enthalpies to estimate the enthalpy change for the following gas-phase reaction: CH4 + Cl2 --> CH2Cl2 + H2 170 kJ/mol -1263 kJ/mol 24 kJ/mol 390 kJ/mol -24 kJ/mol 717 kJ/mol

-24 kJ/mol

What is the formal charge on the chlorine atom in the chlorite ion ClO2 - and the chlorate ion ClO3 -? 3+, 5+ 1+, 2+ 0, 1+ 1+ in both 2+ in both

1+, 2+

The distance between two adjacent atoms in a certain metal is 2.62 Å. What is the atomic radius of an atom? 2.62 Å 5.24 Å 1.31 Å

1.31 Å

How many valence electrons are shown in the Lewis structure of CN-? 10 8 9 12 13

10

What is the coefficient of H2O when the following equation is completed and balanced? Ba (s) + H2O (l) → 5 1 3 2 Ba(s) does not react with H2O (l).

2

How many pairs of electrons are there around the central atom in the Lewis structure of ICl2 -? 5 3 4 2

5

How many pairs of electrons are there around the central atom in the Lewis structure of SeF4? 6 2 3 5 4

5

Using Lewis structures that satisfy the octet rule, determine the number of electrons around the central S atom in SO3 2- and SO4 2-. 6, 8 6, 12 10, 10 8, 12 8, 8

8, 8

In which of the following atoms is the 3s orbital closest to the nucleus? Cl The 3s orbitals are the same distance from the nucleus in all of these atoms. At Br I

At

For each of the following pairs, which element will have the greater metallic character: Li, Be and Li, Na? Li, Li Be, Li Li, Na Be, Na

Li, Na

Which of the following has the highest ionization energy? Na, Na +, K +, Mg 2+? K + Na Na + Mg 2+

Mg 2+

Which of the following is the largest atom? Rb Mg Al Ca Sr B

Rb

Which one of the following atoms has the largest radius? Y Rb Sr Ca K

Rb

Which of the following has the largest first-ionization energy? K, Ca, Fe, Cu, Ge, S Fe S Cu Ge Ca K

S

The most common and stable allotrope of sulfur is __________. S2 S S4 S8 Sulfur does not form allotropes.

S8

Which one of the following beverages originally contained lithium salts? Seven-Up Coca-Cola Pepsi-Cola Gatorade Koolaid

Seven-Up

Write Lewis structures for the following: (i) HOBr (ii) H2O2 (the O atoms are bonded to one another) (iii) H2CO (both H atoms are bonded to C) Pick the incorrect response below. The total number of bonds in structure ii is three. There are three nonbonding pairs of electrons around bromine in structure i. There is a double bond in structure iii. There are double bonds between the oxygens in structure ii.

There are double bonds between the oxygens in structure ii.

Consider the molecule H2N-CH2-CH2-CO2H. Examine the Lewis structure for this molecule and determine which of the following statements is incorrect. There are eleven single bonds in this molecule. There is one double bond in this molecule. There are three single bonds and one lone pair of electrons around the N atom. There are five lone pairs of electrons in this molecule. There is one oxygen-oxygen bond in this molecule.

There is one oxygen-oxygen bond in this molecule.

Of the following metals, __________ exhibits multiple oxidation states. Al V Cs Na Ca

V

phosphorus

Which of these elements has the highest first-ionization energy? platinum potassium polonium palladium phosphorus

potassium

Which of these elements has the highest second-ionization energy? phosphorus platinum potassium palladium polonium

copper

Which of these metals has the most negative electron affinity? cobalt calcium cadmium chromium copper

Of the elements below, __________ has the most negative electron affinity. hydrogen sodium oxygen fluorine chlorine

fluorine

All of the halogens __________. tend to form negative ions of several different charges exhibit metallic character exist under ambient conditions as diatomic gases form salts with alkali metals with the formula MX tend to form positive ions of several different charges

form salts with alkali metals with the formula MX

The Lewis structures of which of the following compounds obey the octet rule? (i) SO3 2- (ii) BH3 (iii) I3 - (iv) AsF6 - (v) O2 - iv ii v iii i and v i

i

Which nonmetal exists as a diatomic solid? phosphorus antimony bromine boron iodine

iodine

Is the C-O bond in CH3OH longer or shorter than the C-O bond in CH3COCH3? Why? They are the same length. shorter; CH3COCH3 has a double bond. shorter; CH3COCH3 has a triple bond. longer; CH3COCH3 is a bigger molecule. longer; CH3COCH3 has a double bond.

longer; CH3COCH3 has a double bond.

Oxides of the active metals combine with water to form __________. metal hydrides water and a salt hydrogen gas metal hydroxides oxygen gas

metal hydroxides

Most of the elements on the periodic table are __________. gases metals liquids metalloids nonmetals

metals

Electrons in the 1s subshell are much closer to the nucleus in Ar than in He due to the larger __________ in Ar. Hund's rule azimuthal quantum number nuclear charge paramagnetism diamagnetism

nuclear charge

Metals can be __________ at room temperature. solid or liquid solid, liquid, or gas liquid only liquid or gas solid only

solid or liquid

Which of the following traits characterizes the alkali metals? existence as diatomic molecules the lowest first ionization energies in a period very high melting point the smallest atomic radius in a period formation of dianions

the lowest first ionization energies in a period

Of the following elements, which have been shown to form compounds? helium neon argon krypton xenon xenon only None of these can form compounds. xenon and argon xenon, krypton, and argon xenon and krypton

xenon, krypton, and argon

Which of the following sequences of ionization energies is incorrect? F > O > C O > S > Se K > Na > Li K > Rb > Cs V > Ca > K

K > Na > Li

Which will be closer to the nucleus: the n = 3 electron shell in Ar or the n = 3 shell in Kr? Kr Ar

Kr

The C-O bond lengths in H2CO are shorter than would be expected for C-O single bonds. Rationalize this observation. Oxygen is more electronegative than carbon. The two hydrogens form bonds with each other. A double bond is formed. A triple bond is formed. Carbon uses its d electrons to form stronger bonds.

A double bond is formed.

Which equation correctly represents the first ionization of aluminum? Al (g) + e- → Al- (g) Al (g) → Al+ (g) + e- Al- (g) → Al (g) + e- Al+ (g) + e- → Al (g) Al (g) → Al- (g) + e-

Al (g) → Al+ (g) + e-

Which ion in the isoelectronic series below has the smallest radius in a crystal? F - N 3- Al 3+ O 2- Na +

Al 3+

In which choice below are the elements ranked in order of increasing first-ionization energy? Ar, Cl, S, Si, Al Al, S, Si, Cl, Ar Al, Si, S, Cl, Ar Cl, S, Al, Ar, Si

Al, Si, S, Cl, Ar

Which atom would have a fourth-ionization energy very much greater than the third? C Li Be B N

B

If successive ionization energies are numbered 1, 2, 3, etc., arrange the following in increasing order (lowest one first, etc.). A: I1 for LiB: I1 for NaC: I2 for LiD: I2 for Be A A B B B

B (4th from top)

Which of the following sets of elements is in the correct order of increasing atomic radius (smallest one first, etc.)? B, Al, Ga Ga, Ge, As P, S, C As, S, P I, Br, Cl

B, Al, Ga

Of the following species, __________ has the largest radius. Sr 2+ Rb + Ar Br - Kr

Br -

For each of the following pairs, indicate which element has the larger first-ionization energy: Ge, Br and P, O. Br, P Br, O Ge, O Ge, P

Br, O

Which of the following orders of electronegativity is incorrect? Se C Si I C

C

Which of the following molecules has two resonance structures? ClO4 - CH3CO2 - CO2 CH4 NO3 -

CH3CO2 -

Which of the following elements has the largest first-ionization energy? Sr Rb Ca K

Ca

If Na reacts with element X to form an ionic compound with the formula Na3X, then Ca will react with X to form Ca3X2 CaX Ca2X3 CaX2

Ca3X2

Which element would be expected to have chemical and physical properties closest to those of fluorine? O Ne Fe Cl S

Cl

Which of the following has the most negative electron affinity? Ar Na Cl Se I

Cl

Write a single Lewis structure that satisfies the octet rule for ClO2 -. What are the formal charges? Cl 1-; O 1+ Cl 1-; O 0 Cl 1+; O 1- Cl 0; O 0 Cl 0; O 0; O 1-

Cl 1+; O 1-

Which of the following sets of elements is arranged in the correct order of decreasing ionization energy (highest energy first, etc.)? As, S, F Sb, Te, I Rb, K, Ca Cl, Br, I K, Na, Li

Cl, Br, I

Which of the following sets of elements is in the incorrect order of increasing atomic radius (smallest one first, etc.)? P, Si, Al Cl, S, O Cl, Br, I Se, As, Sb S, As, Sn

Cl, S, O

__________ is isoelectronic with argon and __________ is isoelectronic with neon. F+, F- Cl-, Cl+ Ne-, Kr+ Cl-, F- Ne-, Ar+

Cl-, F-

In which atom do we find the largest occupied 3d orbital? Al Mg As Ga Ca

Ga

Which one of the following is a metalloid? S Br C Pb Ge

Ge

Which of the following does not exhibit bond resonance? H2O2 SO42- CO32- O3 NO2-

H2O2

Arrange the following in order of increasing C-C bond lengths: HCCH, H2CCH2, H3CCH3 H3CCH3 2CCH2 HCCH 3CCH3 2CCH2 HCCH 2CCH2 3CCH3 H2CCH2 3CCH3

HCCH 2CCH2 3CCH3

In which of the following atoms is the 1s orbital the smallest? I B Cl Br The 1s orbitals in all of these atoms are the same size.

I

*Arrange the following atoms in order of increasing distance of the n = 4 electron shell from the nucleus: Rb, Ca, As, Ir, and Zr. Ir Ca Ir Correct! Ir Ir

Ir (4th from top)

Which of the following elements would have the largest second-ionization energy? Ca Sc Sr K

K

Which of the following oxides is (are) ionic? SO2, MgO, Li2O, N2O N2O MgO MgO and N2O MgO and Li2O SO2 and N2O

MgO and Li2O

Arrange the following atoms in order of increasing atomic radius: N, K, As, Fr N Fr Correct! N As

N (3rd from top)

What is the number of bonding and nonbonding electron pairs around the central atom in each of the following? NH3, H2S, CO2 NH3: (3 bonding, 1 nonbonding); H2S: (2 bonding, 2 nonbonding); CO2: (2 bonding, 0 nonbonding) NH3: (3 bonding, 1 nonbonding); H2S: (2 bonding, 2 nonbonding); CO2: (4 bonding, 0 nonbonding) NH3: (3 bonding, 0 nonbonding); H2S: (2 bonding, 2 nonbonding); CO2: (4 bonding, 0 nonbonding) NH3: (3 bonding, 0 nonbonding); H2S: (2 bonding, 1 nonbonding); CO2: (4 bonding, 0 nonbonding) NH3: (3 bonding, 1 nonbonding); H2S: (2 bonding, 1 nonbonding); CO2: (4 bonding, 0 nonbonding)

NH3: (3 bonding, 1 nonbonding); H2S: (2 bonding, 2 nonbonding); CO2: (4 bonding, 0 nonbonding)

Predict the order of the N-O bond lengths in NO +, NO2 -, and NO3 -. NO+ shortest, NO3- longest NO3- shortest, NO2- longest NO+ longest, NO2- shortest NO+ shortest, NO2- longest

NO+ shortest, NO3- longest

Based on their positions in the periodic table, predict which atom of the following pairs will have the larger first-ionization energy: O, Ne and Mg, Sr. O, Mg Ne, Sr Ne, Mg O, Sr

Ne, Mg

Rank the elements C, O, Na, and Al in order of decreasing ionization energy (largest first, etc.). O > C > Al > Na Na > Al > C > O O > C > Na > Al O > Na > C > Al C > O > Na > Al

O > C > Al > Na

In which set of elements would all members be expected to have very similar chemical properties? Ne, Na, Mg Na, Mg, K O, S, Se N, O, F S, Se, Si

O, S, Se

In which of the following are there two bonding pairs and two nonbonding pairs on an atom? PH3 BeCl2 BF3 NCl3 Correct! OF2 CH4

OF2