ap chemistry - center for teaching &...
TRANSCRIPT
Slide 1 / 113 Slide 2 / 113
AP Chemistry
The Atom
2015-08-25
www.njctl.org
Slide 3 / 113
Table of Contents: The Atom (Pt. B)
· Periodic Table
· Periodic Trends
Click on the topic to go to that section
Slide 4 / 113
Periodic Table
Return to Tableof Contents
Slide 5 / 113
Recall that the periodic law states that the physical and chemical properties of the elements tend to recur in a systematic way when
arranged by increasing atomic number.
The Periodic Law
Slide 6 / 113
Special Groups
Some groups have distinctive properties and are given special names.
Alk
ali M
etal
sA
lkal
ine
Eart
h M
etal
s
Hal
ogen
sN
oble
Gas
es
Transition Metals
Slide 7 / 113
1 What is the atomic number for the element in period 3, group 16?
Slide 7 (Answer) / 113
1 What is the atomic number for the element in period 3, group 16?
[This object is a pull tab]
Ans
wer
16
Slide 8 / 113
2 What is the atomic number for the element in period 5, group 3?
Slide 8 (Answer) / 113
2 What is the atomic number for the element in period 5, group 3?
[This object is a pull tab]A
nsw
er
6
Slide 9 / 113
3 To which group on the periodic table does Neon belong?
A Alkali Metals
B Transition Metals
C Noble GasesD Alkaline Earth Metals
Slide 9 (Answer) / 113
3 To which group on the periodic table does Neon belong?
A Alkali Metals
B Transition Metals
C Noble GasesD Alkaline Earth Metals
[This object is a pull tab]
Ans
wer
C
Slide 10 / 113
4 To which group on the periodic table does Iron belong?
A Alkali Metals
B Transition Metals
C Halogens
D Alkaline Earth Metals
Slide 10 (Answer) / 113
4 To which group on the periodic table does Iron belong?
A Alkali Metals
B Transition Metals
C Halogens
D Alkaline Earth Metals
[This object is a pull tab]
Ans
wer
B
Slide 11 / 113
5 To which group on the periodic table does Beryllium belong?
A Alkali Metals
B Transition Metals
C Halogens
D Alkaline Earth Metals
Slide 11 (Answer) / 113
5 To which group on the periodic table does Beryllium belong?
A Alkali Metals
B Transition Metals
C Halogens
D Alkaline Earth Metals
[This object is a pull tab]A
nsw
er
D
Slide 12 / 113
6 Two elements are studied. One with atomic number X and one with atomic number X+1. It is known that element X is a Noble Gas. Which group on the periodic table is X+1 in?
A Transition Metals
B Halogens
C Alkali Metals
D There is no way to tell
Slide 12 (Answer) / 113
6 Two elements are studied. One with atomic number X and one with atomic number X+1. It is known that element X is a Noble Gas. Which group on the periodic table is X+1 in?
A Transition Metals
B Halogens
C Alkali Metals
D There is no way to tell
[This object is a pull tab]
Ans
wer
C
Slide 13 / 113
1A 2A 8A 1 2 183A 4A 5A 6A 7A
13 14 15 16 17 8B3B 4B 5B 6B 7B 1B 2B 3 4 5 6 7 8 9 10 11 12
}
There are two methods for labeling the groups, the older method shown in black on the top and the newer method shown in blue on the bottom.
Periodic Table & Electron Configuration
Slide 14 / 113
Click here to view an Interactive Periodic Table that shows orbitals for each Element
Click here for an electron orbital game.
Periodic Table & Electron Configuration
Slide 15 / 113
7 The highlighted elements below are in the
A s blockB d blockC p blockD f block
Slide 15 (Answer) / 113
7 The highlighted elements below are in the
A s blockB d blockC p blockD f block
[This object is a pull tab]A
nsw
er
B
Slide 16 / 113
8 The highlighted elements below are in the
A s blockB d blockC p blockD f block
Slide 16 (Answer) / 113
8 The highlighted elements below are in the
A s blockB d blockC p blockD f block
[This object is a pull tab]
Ans
wer
A
Slide 17 / 113
9 The highlighted elements below are in the
A s blockB d blockC p blockD f block
Slide 17 (Answer) / 113
9 The highlighted elements below are in the
A s blockB d blockC p blockD f block
[This object is a pull tab]
Ans
wer
D
Slide 18 / 113
10 The electron configuration ending ns2p6 belongs in which group of the periodic table
A Alkali MetalsB Alkaline Earth MetalsC HalogensD Noble Gases
Slide 18 (Answer) / 113
10 The electron configuration ending ns2p6 belongs in which group of the periodic table
A Alkali MetalsB Alkaline Earth MetalsC HalogensD Noble Gases
[This object is a pull tab]
Ans
wer
D
Slide 19 / 113
11 An unknown element has an electron configuration ending in s2. It is most likely in which group?
A Alkaline Earth Metals
B Halogens
C Alkali Metals
D Transition Metals
Slide 19 (Answer) / 113
11 An unknown element has an electron configuration ending in s2. It is most likely in which group?
A Alkaline Earth Metals
B Halogens
C Alkali Metals
D Transition Metals
[This object is a pull tab]
Ans
wer
A
Slide 20 / 113
Shorthand ConfigurationsNoble Gas elements are used to write shortened electron configurations.
To write a Shorthand Configuration for an element:
(1) Write the Symbol of the Noble Gas element from the row before it in brackets [ ].
(2) Add the remaining electrons by starting at the s orbital of the row that the element is in until the configuration is complete.
Slide 21 / 113
12 What would be the expected "shorthand" electron configuration for Sulfur (S)?A [He]3s23p4
B [Ar]3s24p4
C [Ne]3s23p3
D [Ne]3s23p4
Slide 21 (Answer) / 113
12 What would be the expected "shorthand" electron configuration for Sulfur (S)?A [He]3s23p4
B [Ar]3s24p4
C [Ne]3s23p3
D [Ne]3s23p4
[This object is a pull tab]
Ans
wer
D
Slide 22 / 113
13 Which of the following represents an electron configuration of a Halogen?
A [He]2s1
B [Ne]3s23p5
C [Ar]4s23d2
D [Kr]5s24d105p4
Slide 22 (Answer) / 113
13 Which of the following represents an electron configuration of a Halogen?
A [He]2s1
B [Ne]3s23p5
C [Ar]4s23d2
D [Kr]5s24d105p4
[This object is a pull tab]
Ans
wer
B
Slide 23 / 113
14 The electron configuration [Ar]4s23d5 belongs in which group of the periodic table
A Alkali MetalsB Alkaline Earth MetalsC Transition MetalsD Halogens
Slide 23 (Answer) / 113
14 The electron configuration [Ar]4s23d5 belongs in which group of the periodic table
A Alkali MetalsB Alkaline Earth MetalsC Transition MetalsD Halogens
[This object is a pull tab]
Ans
wer
B
Slide 24 / 113
15 Which of the following represents an electron configuration of an alkaline earth metal?
A [He]2s1
B [Ne]3s23p6
C [Ar]4s23d2
D [Xe]6s2
Slide 24 (Answer) / 113
15 Which of the following represents an electron configuration of an alkaline earth metal?
A [He]2s1
B [Ne]3s23p6
C [Ar]4s23d2
D [Xe]6s2
[This object is a pull tab]
Ans
wer
D
Slide 25 / 113
Stability
When the elements were studied scientists noticed that some of them do not react in certain situations in which others do. These elements were labeled "stable" because they did not change easily. When these stable elements were grouped together, it was noted that periodically, there were patterns in the occurrence of stable elements.
Today we recognize that this difference in stability is due to electron configurations.
Slide 26 / 113
StabilityElements of varying stability fall into one of 3 categories. The most stable atoms have completely full energy levels.
~Full Energy Level ~Full Sublevel (s, p, d, f) ~Half Full Sublevel ( d5, f7)
1234567
67
Slide 27 / 113
StabilityNext in order of stability are elements with full sublevels.
~Full Energy Level ~Full Sublevel (s, p, d, f) ~Half Full Sublevel ( d5, f7)
1234567
67
Slide 28 / 113
StabilityFinally, the elements with half full sublevels are also stable, but not as stable as elements with fully energy levels or sublevels.
~Full Energy Level ~Full Sublevel (s, p, d, f) ~Half Full Sublevel ( d 5, f7)
1234567
67
Slide 29 / 113
16 The elements in the periodic table that have completely filled shells or subshells are referred to as:
A noble gases.
B halogens.
C alkali metals.
D transition elements.
Slide 29 (Answer) / 113
16 The elements in the periodic table that have completely filled shells or subshells are referred to as:
A noble gases.
B halogens.
C alkali metals.
D transition elements.
[This object is a pull tab]
Ans
wer
A
Slide 30 / 113
17 Alkaline earth metals are more stable than alkali metals because...
A they have a full shell.
B they have a full subshell.
C they have a half-full subshell.
D they contain no p orbitals.
Slide 30 (Answer) / 113
17 Alkaline earth metals are more stable than alkali metals because...
A they have a full shell.
B they have a full subshell.
C they have a half-full subshell.
D they contain no p orbitals.
[This object is a pull tab]
Ans
wer
B
Slide 31 / 113
18 The elements in the periodic table which lack one electron from a filled shell are referred to as:
A noble gases.
B halogens.
C alkali metals.
D transition elements.
Slide 31 (Answer) / 113
18 The elements in the periodic table which lack one electron from a filled shell are referred to as:
A noble gases.
B halogens.
C alkali metals.
D transition elements.
[This object is a pull tab]
Ans
wer
B
Slide 32 / 113
Electron Configuration Exceptions
You should know the basic exceptions in the d- and f-sublevels. These fall in the circled areas on the table below.
1234567
67
Slide 33 / 113
Chromium Expect: [Ar] 4s2 3d4 Actually: [Ar] 4s1 3d5
For some elements, in order to exist in a more stable state, electrons from an s sublevel will move to a d sublevel, thus providing the stability of a half-full sublevel. To see why this can happen we need to examine how "close" d and s sublevels are.
Electron Configuration Exceptions
1234567
67
Cr
Slide 34 / 113
12
3
4
5
6
7
1s
2s
2p
3s
3p4s
3d4p
5s
4d5p
6s 4f5d
6p5f7s
6d7p
6f7d
7f
Ene
rgy
Energies of Orbitals
Because of how close the f and d orbitals are to the s orbitals an electron very little energy is required to move an electron from the s orbital (leaving it half full) to the f or d orbital, causing them to also be half full.
(It's kind of like borrowing a cup of sugar from a neighbor. You'd only borrow it from someone you were close to and only if you needed it.)
Slide 35 / 113
CopperExpected: [Ar] 4s2 3d9 Actual: [Ar] 4s1 3d10
Copper gains stability when an electron from the 4sorbital fills the 3d orbital.
Electron Configuration Exceptions
1234567
67
Cu
Slide 36 / 113
19 The electron configuration for Copper (Cu) is
A [Ar] 4s24d9
B [Ar] 4s14d9
C [Ar] 4s23d9
D [Ar] 4s13d10
Slide 36 (Answer) / 113
19 The electron configuration for Copper (Cu) is
A [Ar] 4s24d9
B [Ar] 4s14d9
C [Ar] 4s23d9
D [Ar] 4s13d10
[This object is a pull tab]
Ans
wer
D
Slide 37 / 113
20 What would be the expected "shorthand" electron configuration for Silver (Ag)?A [Kr]5s25d9
B [Ar]5s14d10
C [Kr]5s24d9
D [Kr]5s14d10
Slide 37 (Answer) / 113
20 What would be the expected "shorthand" electron configuration for Silver (Ag)?A [Kr]5s25d9
B [Ar]5s14d10
C [Kr]5s24d9
D [Kr]5s14d10
[This object is a pull tab]
Ans
wer
D
Slide 38 / 113
21 What would be the expected "shorthand" electron configuration for Molybdenum (Mb)?A [Kr]5s25d4
B [Ar]5s24d4
C [Kr]5s14d5
D [Kr]5s24d4
Slide 38 (Answer) / 113
21 What would be the expected "shorthand" electron configuration for Molybdenum (Mb)?A [Kr]5s25d4
B [Ar]5s24d4
C [Kr]5s14d5
D [Kr]5s24d4
[This object is a pull tab]
Ans
wer
C
Slide 39 / 113
Periodic Trends
Return to Tableof Contents
Slide 40 / 113
Periodic Trends
There are four main trends in the periodic table:
Size or radius of atoms/ionsElectronegativityIonization energyMetallic character
Slide 41 / 113
Periodic Trends
These four periodic trends are all shaped by the interactions between the positive charge of the atomic nucleus and the
negative charges of electrons.
Slide 42 / 113
Effective Nuclear Charge
In a multi-electron atom, electrons are both attracted to the positive nucleus and repelled by other electrons.
The nuclear charge that an electron experiences depends on both factors.
For example, here's sodium.
Valence 3s electron
[Ne] inner shell electrons (10-)
Nucleus (11+)
10-
11+
-
Combined effect = 11-10 = 1+
Slide 43 / 113
This is the effective nuclear charge experience by the valence electron. The inner shell electrons are shielding the outermost electron from experiencing all but +1 e worth of charge!
The effective nuclear charge (Zeff) is found by Zeff = Z − S
Effective Nuclear Charge
Valence 3s electron
S (inner shell electrons) = 10-
Z = 11+
Zeff = 11-10 = 1+
10-
11+
-
Z is the atomic number (number of protons)
S is the shielding constant and represents the number of electrons in the inner shells of an atom.
Slide 44 / 113
22 Two elements are studied. One with atomic number X and one with atomic number X+1. Assuming element X is not a Noble Gas, which element has the larger shielding constant?
A Element X
B Element X+1
C They are both the same
D More information is needed
Slide 44 (Answer) / 113
22 Two elements are studied. One with atomic number X and one with atomic number X+1. Assuming element X is not a Noble Gas, which element has the larger shielding constant?
A Element X
B Element X+1
C They are both the same
D More information is needed
[This object is a pull tab]
Ans
wer
C
Slide 45 / 113
23 Two elements are studied. One with atomic number X and one with atomic number X+1. It is known that element X is a Noble Gas. Which element has the larger shielding constant?
A Element X
B Element X+1
C They are both the same
D More information is needed
Slide 45 (Answer) / 113
23 Two elements are studied. One with atomic number X and one with atomic number X+1. It is known that element X is a Noble Gas. Which element has the larger shielding constant?
A Element X
B Element X+1
C They are both the same
D More information is needed
[This object is a pull tab]
Ans
wer
B
Slide 46 / 113
24 In which subshell does an electron in a calcium atom experience the greatest effective nuclear charge? A 1s
B 2sC 3sD 3p
Slide 46 (Answer) / 113
24 In which subshell does an electron in a calcium atom experience the greatest effective nuclear charge? A 1s
B 2sC 3sD 3p
[This object is a pull tab]
Ans
wer
A
Slide 47 / 113
Let's examine the trend in atomic radii for the first 18 elements.
atomic number
radius (pm)
0
200
100
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
H
LiNa
HeNe
Ar
We clearly see two trends!
1. As atomic number increases down a group, the radii increase. Why?
H < Li < Na
2. As atomic number increases across a period, the radii decrease. Why?
Li > Be > B > C > N > O > F > Ne
Atomic Radii
Slide 47 (Answer) / 113
Let's examine the trend in atomic radii for the first 18 elements.
atomic number
radius (pm)
0
200
100
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
H
LiNa
HeNe
Ar
We clearly see two trends!
1. As atomic number increases down a group, the radii increase. Why?
H < Li < Na
2. As atomic number increases across a period, the radii decrease. Why?
Li > Be > B > C > N > O > F > Ne
Atomic Radii
[This object is a pull tab]
Ans
wer
1. An additional energy shell is gained increasing the atomic radii.
2. The effective nuclear charge increase, creating a stronger
Coulombic attraction between the nucleus and the valence electrons.
Slide 48 / 113
25 What is Zeff for Boron (B)?
5+
Slide 48 (Answer) / 113
25 What is Zeff for Boron (B)?
5+
[This object is a pull tab]
Ans
wer
3
Slide 49 / 113
26 Compare the radial size of boron to lithium and beryllium.
A Li>Be>B
B Li<Be<B
C Li>B>Be
D Be<Li<B
Slide 49 (Answer) / 113
26 Compare the radial size of boron to lithium and beryllium.
A Li>Be>B
B Li<Be<B
C Li>B>Be
D Be<Li<B
[This object is a pull tab]A
nsw
er
A
Slide 50 / 113
27 What is Zeff for Carbon (C)?
6+
Slide 50 (Answer) / 113
27 What is Zeff for Carbon (C)?
6+
[This object is a pull tab]
Ans
wer
4
Slide 51 / 113
28 Compare the radial size of carbon to boron and nitrogen.
A C>N>B
B C<N<B
C B>C>N
D B<C<N
Slide 51 (Answer) / 113
28 Compare the radial size of carbon to boron and nitrogen.
A C>N>B
B C<N<B
C B>C>N
D B<C<N
[This object is a pull tab]
Ans
wer
C
Slide 52 / 113
29 Which of the following equations correctly calculates the Coulombic force between the valence electrons and the nucleus of an oxygen atom?
A F = k(2e)2/r2
B F = k(4e)2/r2
C F = k(6e)2/r2
D F = k(8e)2/r2
Slide 52 (Answer) / 113
29 Which of the following equations correctly calculates the Coulombic force between the valence electrons and the nucleus of an oxygen atom?
A F = k(2e)2/r2
B F = k(4e)2/r2
C F = k(6e)2/r2
D F = k(8e)2/r2[This object is a pull tab]
Ans
wer
B
Slide 53 / 113
30 Given the atomic number of the smallest element in the 2nd period.
Slide 53 (Answer) / 113
30 Given the atomic number of the smallest element in the 2nd period.
[This object is a pull tab]
Ans
wer
10
Slide 54 / 113
31 Across a period from left to right Zeff _____________.
A increases
B decreasesC remains the same
Slide 54 (Answer) / 113
31 Across a period from left to right Zeff _____________.
A increases
B decreasesC remains the same
[This object is a pull tab]
Ans
wer
A
Slide 55 / 113
32 Down a group from top to bottom Zeff _____________.
A increases
B decreasesC remains the same
Slide 55 (Answer) / 113
32 Down a group from top to bottom Zeff _____________.
A increases
B decreasesC remains the same
[This object is a pull tab]
Ans
wer
C
Slide 56 / 113
33 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
Slide 56 (Answer) / 113
33 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
[This object is a pull tab]
Ans
wer
A
Slide 57 / 113
34 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
Slide 57 (Answer) / 113
34 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
[This object is a pull tab]
Ans
wer
B
Slide 58 / 113
35 Of the following, which gives the correct order for atomic radius for Mg, Na, P, Si and Ar?
A Mg > Na > P > Si > Ar
B Ar > Si > P > Na > Mg
C Si > P > Ar > Na > Mg
D Na > Mg > Si > P > Ar
Slide 58 (Answer) / 113
35 Of the following, which gives the correct order for atomic radius for Mg, Na, P, Si and Ar?
A Mg > Na > P > Si > Ar
B Ar > Si > P > Na > Mg
C Si > P > Ar > Na > Mg
D Na > Mg > Si > P > Ar
[This object is a pull tab]
Ans
wer
D
Slide 59 / 113
36 Which of the following atoms would have a smaller atomic radii than Ar and why?
A Fe - It has more core electrons
B Si - It has fewer core electrons
C O - It has fewer core electrons
D Ne - it has a higher nuclear charge (Z)
Slide 59 (Answer) / 113
36 Which of the following atoms would have a smaller atomic radii than Ar and why?
A Fe - It has more core electrons
B Si - It has fewer core electrons
C O - It has fewer core electrons
D Ne - it has a higher nuclear charge (Z)
[This object is a pull tab]
Ans
wer
C
Slide 60 / 113
37 Two elements are studied. One with atomic number X and one with atomic number X+1. Assuming element X is not a Noble Gas, which element has the larger atomic radius?
A Element X
B Element X+1
C They are both the same
D More information is needed
Slide 60 (Answer) / 113
37 Two elements are studied. One with atomic number X and one with atomic number X+1. Assuming element X is not a Noble Gas, which element has the larger atomic radius?
A Element X
B Element X+1
C They are both the same
D More information is needed
[This object is a pull tab]
Ans
wer
A
Slide 61 / 113
38 Two elements are studied. One with atomic number X and one with atomic number X+1. It is known that element X is a Noble Gas. Which element has the larger atomic radius?
A Element X
B Element X+1
C They are both the same
D More information is needed
Slide 61 (Answer) / 113
38 Two elements are studied. One with atomic number X and one with atomic number X+1. It is known that element X is a Noble Gas. Which element has the larger atomic radius?
A Element X
B Element X+1
C They are both the same
D More information is needed
[This object is a pull tab]A
nsw
er
B
Slide 62 / 113
Ionic RadiiWhen electrons are gained or lost, the effect on the radii can be
dramatic or slight but there are some certainties.
If an atom loses electrons, the radii will
decrease. Why?
Ca --> Ca2+ + 2e-
194 pm 99 pm
When electrons are lost, the remaining electrons feel a
stronger coulombic attraction from the nucleus.
If an atom gains electrons, the radii will
increase. Why?
F + e- --> F-
42 pm 136 pm
When electrons are gained, the nuclear charge is spread
over a larger number of electrons, resulting in a
weaker coulombic attraction.
Answer Answer
Slide 63 / 113
Ionic RadiiLet's rank a series of atoms and ions in order of increasing radii.
Al3+ Al Mg Mg2+
Whenever comparing radii, use the following procedure:
1. Determine the energy level of the atom/ion.
2. For atoms in the same energy level, use the nuclear charge (Z) to determine the radii.
Al3+ Al Mg Mg2+
Energy Level 2 3 3 2
"Z" 13 13 12 12
Al3+ < Mg2+ < Al < Mg
radius (pm) 50 < 65 < 118 < 145
Slide 64 / 113
In this case, Na+, Mg2+, Al3+, O2-, and F- are all isoelectronic with Ne. As a result, they all experience the same core shielding.
The ionic radii then decreases with an increasing nuclear charge.Al3+ < Mg2+ < Na+ < F- < O2-
Z = 13 12 11 9 8
Ionic RadiiBelow is an example of an isoelectronic series. In an isoelectronic
series the atoms/ions have the same number of electrons.
Slide 65 / 113
39 Which of the following influences the atomic/ionic radii?
A the number of neutrons
B the amount of core electrons between the nucleus and the valence electrons
C the number of protons
D B and C
Slide 65 (Answer) / 113
39 Which of the following influences the atomic/ionic radii?
A the number of neutrons
B the amount of core electrons between the nucleus and the valence electrons
C the number of protons
D B and C
[This object is a pull tab]
Ans
wer
D
Slide 66 / 113
40 Which ion below has the largest radius?
A O2-
B Li+
C I-
D N3-
Slide 66 (Answer) / 113
40 Which ion below has the largest radius?
A O2-
B Li+
C I-
D N3-
[This object is a pull tab]
Ans
wer
C
Slide 67 / 113
41 Which of the following pairs correctly shows the proper relationship between the two atoms/ions in terms of atomic/ionic radii?
A Ca < Ca2+
B F < F-
C V < Mn
D Ca < Be
Slide 67 (Answer) / 113
41 Which of the following pairs correctly shows the proper relationship between the two atoms/ions in terms of atomic/ionic radii?
A Ca < Ca2+
B F < F-
C V < Mn
D Ca < Be[This object is a pull tab]
Ans
wer
B
Slide 68 / 113
42 Which of the following would correctly rank the following in order of decreasing atomic/ionic radii?
A V4+ > V5+ > F > F-
B V4+ > V5+ > F- > F
C V5+ > V4+ > F- > F
D V5+ > V4+ > F > F-
Slide 68 (Answer) / 113
42 Which of the following would correctly rank the following in order of decreasing atomic/ionic radii?
A V4+ > V5+ > F > F-
B V4+ > V5+ > F- > F
C V5+ > V4+ > F- > F
D V5+ > V4+ > F > F-
[This object is a pull tab]
Ans
wer
B
Slide 69 / 113
43 Isotopes of an element, like C-12 and C-13, are likely to have different atomic radii?
Yes
No
Slide 69 (Answer) / 113
43 Isotopes of an element, like C-12 and C-13, are likely to have different atomic radii?
Yes
No
[This object is a pull tab]
Ans
wer
NO
Slide 70 / 113
Electronegativity
Since the electromagnetic force decreases rapidly as distance increases, we could say that the distance between charges affects an atoms ability to hold onto electrons more than the actual number of protons in the nucleus.
Applying Coulomb's Law:
FE # 1/ r2 FE # qnucleus
Of course, if the distance doesn't change much and the number of protons does, then the electrons will still be held to the atom tightly.
Slide 71 / 113
Electronegativity Trends
Electronegativity is a measure of the ability of atoms in a molecule to attract electrons to themselves.
On the periodic chart, electronegativity increases as you go…
from left to right across a row
from the bottom to the top of a column
Slide 72 / 113
Slide 73 / 113
Electronegativity
There are two notable exceptions to this.
Electronegativity is very closely related to atomic size.
Generally, as atomic size decreases, electronegativity increases.
Can you explain why there is a direct relationship between atomic size and electronegativity?
Slide 73 (Answer) / 113
Electronegativity
There are two notable exceptions to this.
Electronegativity is very closely related to atomic size.
Generally, as atomic size decreases, electronegativity increases.
Can you explain why there is a direct relationship between atomic size and electronegativity?
[This object is a pull tab]
Ans
werThe smaller the radius, the greater
the electrostatic force on the valence electrons
Slide 74 / 113
Electronegativity Exception #1
The Noble Gases are some of the smallest atoms, but are usually left out of electronegativity trends since they neither want electrons nor want to get rid of electrons.
Using your knowledge of electron configurations, why do you think noble gases are left out of electronegativity trends?
Slide 74 (Answer) / 113
Electronegativity Exception #1
The Noble Gases are some of the smallest atoms, but are usually left out of electronegativity trends since they neither want electrons nor want to get rid of electrons.
Using your knowledge of electron configurations, why do you think noble gases are left out of electronegativity trends?
[This object is a pull tab]
Ans
wer Because noble gases have a full
shell they are stable. Gaining or losing an electron would decrease
the stability of a noble gas atom
Slide 75 / 113
The Transition Metals have some unexpected trends in electronegativity because of their d and sometimes f orbitals.
Electronegativity Exception #2
The electrons located in the 3d orbitals (and all d and f orbitals after that) do not contribute as much to the shielding constants of the elements as electrons in the s and p orbitals.
As such, elements with configurations that end in a d or f orbital will frequently have atomic radii that do not match up with the normal trend.
Slide 76 / 113
44 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 decreases, decreases
Slide 76 (Answer) / 113
44 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 decreases, decreases
[This object is a pull tab]
Ans
wer
C
Slide 77 / 113
45 Which of the following correctly ranks the elements from highest to lowest electronegativity?
A Cl > S > P
B Br > Cl > FC K > Na > Li
D N > O > F
Slide 77 (Answer) / 113
45 Which of the following correctly ranks the elements from highest to lowest electronegativity?
A Cl > S > P
B Br > Cl > FC K > Na > Li
D N > O > F
[This object is a pull tab]
Ans
wer
A
Slide 78 / 113
46 Which of the following BEST explains why fluorine has a higher electronegativity than oxygen?
A F has a higher nuclear charge and less shielding than O
B F has a higher nuclear charge and similar shielding of O
C F has the equivalent nuclear charge and less shielding than O
D F has the equivalent nuclear charge and more shielding than O
Slide 78 (Answer) / 113
46 Which of the following BEST explains why fluorine has a higher electronegativity than oxygen?
A F has a higher nuclear charge and less shielding than O
B F has a higher nuclear charge and similar shielding of O
C F has the equivalent nuclear charge and less shielding than O
D F has the equivalent nuclear charge and more shielding than O
[This object is a pull tab]
Ans
wer
B
Slide 79 / 113
47 An element with a small electronegativity value is likely to have...
A Valence shell PES peaks with high binding energies
B A high nuclear charge and a low amount of shielding
C A low nuclear charge and a high amount of shielding
D Both A and C
Slide 79 (Answer) / 113
47 An element with a small electronegativity value is likely to have...
A Valence shell PES peaks with high binding energies
B A high nuclear charge and a low amount of shielding
C A low nuclear charge and a high amount of shielding
D Both A and C[This object is a pull tab]
Ans
wer
C
Slide 80 / 113
Ionization Energy
Ca Ca+ + e- Ca+ Ca2+ + e-
The ionization energy is the amount of energy required to remove an electron from the ground state of a gaseous atom or ion.
The first ionization energy is the energy required to remove the first electron.
The second ionization energy is the energy required to remove the second electron, etc.
1e-
1e-
Slide 81 / 113
Trends in First Ionization Energies
How is ionization energy related to electronegativity and Z eff?
Click here for an animation onIonization Energy
Slide 81 (Answer) / 113
Trends in First Ionization Energies
How is ionization energy related to electronegativity and Z eff?
Click here for an animation onIonization Energy
[This object is a pull tab]
Ans
wer In general, ionization energy
increases with increasing electronegativity and effective
nuclear charge.
Slide 82 / 113
Discontinuity #1The first is between Groups 2 and 13 (3A).As you can see on the chart to the right, the ionization energy actually decreases from Group 2 to Group 13 elements. The electron removed for Group 13 elements is from a p orbital and removing this electron actually adds stability.
The electron removed is farther from nucleus, there is a small amount of repulsion by the s electrons.
The atom gains stability by having a full s orbital, and an empty p orbital.
Slide 83 / 113
Discontinuity #2The second is between Groups 15 and 16.
Using your knowledge of electron configurations and the stability of atoms explain why the first ionization energy for a Group 16 element would be less than that for a Group 15 element in the same period.
Slide 83 (Answer) / 113
Discontinuity #2The second is between Groups 15 and 16.
Using your knowledge of electron configurations and the stability of atoms explain why the first ionization energy for a Group 16 element would be less than that for a Group 15 element in the same period.
[This object is a pull tab]
Ans
wer Group 15 is more stable because it
has a half-full sublevel
Slide 84 / 113
48 What is the ionization energy?
A Energy change associated with the gain of an electron
B Measure of the attraction of an atom for electrons when in a compound
C Pull of the neutrons on the electrons
D Amount of energy required to remove an electron from an atom or ion
Slide 84 (Answer) / 113
48 What is the ionization energy?
A Energy change associated with the gain of an electron
B Measure of the attraction of an atom for electrons when in a compound
C Pull of the neutrons on the electrons
D Amount of energy required to remove an electron from an atom or ion
[This object is a pull tab]
Ans
wer
D
Slide 85 / 113
49 Which of the following would NOT influence the ionization energy?
A The shielding from core electrons
B The extent to which an orbital is full
C The nuclear charge
D The number of principal energy levels between the valence electrons and the nucleus
E All of these influence the ionization energy
Slide 85 (Answer) / 113
49 Which of the following would NOT influence the ionization energy?
A The shielding from core electrons
B The extent to which an orbital is full
C The nuclear charge
D The number of principal energy levels between the valence electrons and the nucleus
E All of these influence the ionization energy
[This object is a pull tab]
Ans
wer
E
Slide 86 / 113
50 Which of the following elements would be expected to have a higher ionization energy than magnesium (Mg)?
A Al
B Ca
C Na
D B
Slide 86 (Answer) / 113
50 Which of the following elements would be expected to have a higher ionization energy than magnesium (Mg)?
A Al
B Ca
C Na
D B
[This object is a pull tab]
Ans
wer
D
Slide 87 / 113
51 Which of the following correctly ranks the elements below in order of decreasing ionization energy?
A Ne > O > N
B Ne > N > O
C H > He > Ne
D Li > Mg > Ga
Slide 87 (Answer) / 113
51 Which of the following correctly ranks the elements below in order of decreasing ionization energy?
A Ne > O > N
B Ne > N > O
C H > He > Ne
D Li > Mg > Ga
[This object is a pull tab]
Ans
wer
B
Slide 88 / 113
52 Which of the following pairs are correct in terms of relative first ionization energy and why?
A O2- < Ne , due to smaller nuclear charge on oxide ion
B Li > Na , due to increased shielding in the Na atom
C Zn > Cu , due to a higher nuclear charge in zinc
D Cl > S , due to the smaller nuclear charge in sulfur
E All of these
Slide 88 (Answer) / 113
52 Which of the following pairs are correct in terms of relative first ionization energy and why?
A O2- < Ne , due to smaller nuclear charge on oxide ion
B Li > Na , due to increased shielding in the Na atom
C Zn > Cu , due to a higher nuclear charge in zinc
D Cl > S , due to the smaller nuclear charge in sulfur
E All of these [This object is a pull tab]
Ans
wer
E
Slide 89 / 113
The Periodic Law and Ionization Energy
Unless you're hydrogen, you've got multiple electrons that can be lost. As a result we have to distinguish between 1st, 2nd, 3rd, etc.
ionization energies.
Ionization Ionization Energy
1st: Na + IE --> Na+ + e- 496 kJ/mol
2nd: Na+ + IE --> Na2+ + e- 4560 kJ/mol3rd: Na2+ + IE --> Na3+ + e- 6,900 kJ/mol
4th: Na3+ + IE --> Na4+ + e- 9540 kJ/mol
Note the huge jump in ionization energy from the 1st to the 2nd. After sodium loses it's first electron, it is isoelectronic with [Ne], with
an extremely stable full s and p orbital and minimal shielding.
Each successive ionization energy is always higher than the previous. This is due to the higher nuclear charge felt by the
remaining electrons.
Slide 90 / 113
53 Which of the following elements best fits the data provided below?
A Li
B C
C Be
D Ne
Ionization Ionization Energy
1st: X + IE --> X+ + e- 900 kJ/mol
2nd: X+ + IE --> X2+ + e- 1757 kJ/mol3rd: X2+ + IE --> X3+ + e- 14,850 kJ/mol
Ans
wer
Slide 91 / 113
54 An atom has the following values for its first four ionization energies. Which of the following elements would fit this data?
A Na
B Mg
C SiD F
1st IE = 345 kJ2nd IE = 456 kJ3rd IE = 3,400 kJ4th IE = 3,876 kJ
Slide 91 (Answer) / 113
54 An atom has the following values for its first four ionization energies. Which of the following elements would fit this data?
A Na
B Mg
C SiD F
1st IE = 345 kJ2nd IE = 456 kJ3rd IE = 3,400 kJ4th IE = 3,876 kJ
[This object is a pull tab]
Ans
wer
B
Slide 92 / 113
Ionization Energy and PESIonization energy data can be determined from PES (photoelectron spectroscopy). Recall that PES looks at the energy required to remove electrons from an atom. Each orbital appears as a peak on the spectrum.
The PES spectrum clearly shows that the core electrons require the most energy to remove. It also shows that Be has a higher 1st IE for the removal of the valence electrons than does Li. This is expected as Be has a higher "Z".
Li (1s)
Be (1s)Be (2s)
Li (2s)
Intensity
binding energy
Slide 93 / 113
PES PracticeLet's interpret another PES spectra, this one of nitrogen and oxygen.
Intensity
binding energy
N (2s) N (1s)N (2p)
O (2p)O (2s) O (1s)
Why is the N (2p) peak greater than the O (2p) peak?
Why is the N(2s) peak less than the O (2s) peak?
Slide 93 (Answer) / 113
PES PracticeLet's interpret another PES spectra, this one of nitrogen and oxygen.
Intensity
binding energy
N (2s) N (1s)N (2p)
O (2p)O (2s) O (1s)
Why is the N (2p) peak greater than the O (2p) peak?
Why is the N(2s) peak less than the O (2s) peak? [This object is a pull tab]
Ans
wer N has a half-full "p" orbital
increasing the ionization energy
O has the higher nuclear charge
Slide 94 / 113
Ionization Energy and PES
Click to go to an interactive PES spectra database
and answer the questions.
1. Why is the binding energy of the electrons greater in He than H?
2. Which peak in the Li spectra represents the valence electrons?
3. Why is the valence peak binding energy less in Li than in H?
4. Why is the core peak (1s) binding energy greater in Li than in H?
Slide 94 (Answer) / 113
Ionization Energy and PES
Click to go to an interactive PES spectra database
and answer the questions.
1. Why is the binding energy of the electrons greater in He than H?
2. Which peak in the Li spectra represents the valence electrons?
3. Why is the valence peak binding energy less in Li than in H?
4. Why is the core peak (1s) binding energy greater in Li than in H? [This object is a pull tab]
Ans
wer
1. Similar shielding but greater "Z"
2. Peak with lower binding energy
3. Increased shielding due to core 1s electrons, lessens coulombic force
4. Lithium has a higher nuclear charge "Z" so higher coulombic attractions
Slide 95 / 113
55 The following PES spectrum shows the valence "p" orbital peaks for Si and for C. Which of the following would be TRUE?
A The Si peak is of lower energy due to it's higher nuclear charge
B The Si peak is of higher energy due to the increased shielding from core electrons
C The Si peak is of lower energy due to the increased shielding from core electrons
D The Si peak is of higher energy due to its higher nuclear charge
Intensity
binding energy
Slide 95 (Answer) / 113
55 The following PES spectrum shows the valence "p" orbital peaks for Si and for C. Which of the following would be TRUE?
A The Si peak is of lower energy due to it's higher nuclear charge
B The Si peak is of higher energy due to the increased shielding from core electrons
C The Si peak is of lower energy due to the increased shielding from core electrons
D The Si peak is of higher energy due to its higher nuclear charge
Intensity
binding energy
[This object is a pull tab]
Ans
wer
C
Slide 96 / 113
56 The 3s peak for magnesium should have a higher binding energy than that of the 4s peak in calcium due to calcium's higher amount of shielding by core electrons?
True
False
Slide 96 (Answer) / 113
56 The 3s peak for magnesium should have a higher binding energy than that of the 4s peak in calcium due to calcium's higher amount of shielding by core electrons?
True
False
[This object is a pull tab]
Ans
wer
TRUE
Slide 97 / 113
57 Below is an actual PES spectrum of palladium (Pd). Which of the following would be TRUE? (Note: the outer 5s and 4d peaks are not shown)
A Compared to Pd, the 3d peak in Cd would be found to the left of the 3d Pd peak
B Compared to Pd, the 3d peak in Rb would be of a higher binding energy due to lower nuclear charge
C Compared to Pd, the 3p peak in Kr should be found to the left of the 3p peak in Pd
3s 3p
3d
4p 4s
Slide 97 (Answer) / 113
57 Below is an actual PES spectrum of palladium (Pd). Which of the following would be TRUE? (Note: the outer 5s and 4d peaks are not shown)
A Compared to Pd, the 3d peak in Cd would be found to the left of the 3d Pd peak
B Compared to Pd, the 3d peak in Rb would be of a higher binding energy due to lower nuclear charge
C Compared to Pd, the 3p peak in Kr should be found to the left of the 3p peak in Pd
3s 3p
3d
4p 4s
[This object is a pull tab]A
nsw
er
A
Slide 98 / 113
58 Based on the PES data below, what would be TRUE regarding atoms 1 and 2?
A I only B II and III only C 1 and III only
D II and IV only
Binding Energy
Inte
nsity
0 10
10 100
28.6
1.091.72
Binding Energy
Inte
nsity
0 10
10 100
39.6
1.402.45
1 2
I. Atom 1 has a smaller atomic radii II. Atom 2 has a larger first ionization energy
III. Both atoms are in the same period
IV. Both atoms are in the same group
Slide 98 (Answer) / 113
58 Based on the PES data below, what would be TRUE regarding atoms 1 and 2?
A I only B II and III only C 1 and III only
D II and IV only
Binding Energy
Inte
nsity
0 10
10 100
28.6
1.091.72
Binding Energy
Inte
nsity
0 10
10 100
39.6
1.402.45
1 2
I. Atom 1 has a smaller atomic radii II. Atom 2 has a larger first ionization energy
III. Both atoms are in the same period
IV. Both atoms are in the same group[This object is a pull tab]
Ans
wer
B
Slide 99 / 113
Ionization Energy and Metallic CharacterMetals are generally described as being able to lose
electrons readily which promotes conductivity.
Since metals lose electrons easily, they must have low ionization energies compared to non-metals.
Element Metal or Non-metal1st Ionization
Energy (kJ/mol)Na metal 496
O non-metal 1314
Slide 100 / 113
Ionization Energy and Metallic CharacterWe can predict, based on ionization energies, where the
metals and non-metals are on the periodic table.
semi-metals or metalloids
Notice that an element becomes more metallic as the shielding increases and as the nuclear charge - for a given
level of shielding - decreases.
Slide 101 / 113
59 Which of the following has the elements correctly ordered by increasing metallic character?
A Li < Be < B
B Ca < K < Ga
C Ga < Ca < K
D Rb < Cs < As
Slide 101 (Answer) / 113
59 Which of the following has the elements correctly ordered by increasing metallic character?
A Li < Be < B
B Ca < K < Ga
C Ga < Ca < K
D Rb < Cs < As[This object is a pull tab]
Ans
wer
C
Slide 102 / 113
60 Which of the following ranks the metals in order of increasing reactivity?
A Li < Na < Mg < K
B Mg < Li < Na < K
C K < Li < Na < K
D Li < Fe < Zn < Au
Slide 102 (Answer) / 113
60 Which of the following ranks the metals in order of increasing reactivity?
A Li < Na < Mg < K
B Mg < Li < Na < K
C K < Li < Na < K
D Li < Fe < Zn < Au
[This object is a pull tab]
Ans
wer
B
Slide 103 / 113
61 Which of the following would be TRUE?
A The higher the ionization energy, the less metallic an element will be
B The lower the ionization energy, the less metallic an element will be
C For a given amount of core electron shielding, the higher the nuclear charge, the more metallic an element will be
D Both A and C
Slide 103 (Answer) / 113
61 Which of the following would be TRUE?
A The higher the ionization energy, the less metallic an element will be
B The lower the ionization energy, the less metallic an element will be
C For a given amount of core electron shielding, the higher the nuclear charge, the more metallic an element will be
D Both A and C
[This object is a pull tab]
Ans
wer
A
Slide 104 / 113
62 Why is lead considered a metal and carbon a non-metal despite being in the same group?
A Lead has a greater S value
B Lead has a greater Zeff
C Lead is more electronegative
D All of the above
Slide 104 (Answer) / 113
62 Why is lead considered a metal and carbon a non-metal despite being in the same group?
A Lead has a greater S value
B Lead has a greater Zeff
C Lead is more electronegative
D All of the above[This object is a pull tab]
Ans
wer
A
Slide 105 / 113
The charges of ions is also periodic in nature, as seen on the graph below. The formation of ions depends on ionization energy and electronegativity.
ion charge
+1
+2
+3
-1
-2
-3
atomic number 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
+4
Ionic Charge
Slide 106 / 113
Ionic Charge This trend in ionic charge can be easily explained if we apply the
quantum model of the atom.
Element
Principal Quantum
Number (N) of valence electrons
Electron Configuration
Lose/Gain
electrons
Ionic Charge
H 1 1s1 gain 1
lose 1
-1
+1He 1 1s2 NA NA Li 2 [He]2s1 lose 1 +1Be 2 [He]2s2 lose 2 +2
B 2 [He]2s22p1 lose 3 +3
C 2 [He]2s22p2 lose 4 +4
N 2 [He]2s22p3 gain 3 -3
O 2 [He]2s22p4 gain 2 -2 F 2 [He]2s22p5 gain 1 -1Ne 2 [He]2s22p6 NA NA
Na 3 [Ne]3s1 lose 1 +1
The pattern recurs with every increase in the
principal quantum number. Atoms lose or gain electrons to obtain a full shell or subshell, thereby increasing their
stability.
Slide 107 / 113
63 Which of the following BEST explains why O and S both form ions with a -2 charge?
A They both have the same atomic number
B They are both in the same period
C They both have the same electron configuration
D They both have the same number of valence electrons
Slide 107 (Answer) / 113
63 Which of the following BEST explains why O and S both form ions with a -2 charge?
A They both have the same atomic number
B They are both in the same period
C They both have the same electron configuration
D They both have the same number of valence electrons
[This object is a pull tab]
Ans
wer
D
Slide 108 / 113
64 An atom with the electron configuration of [Kr]5s24d2 would be in the same group as _____ and have a likely charge of ____.
A Sc, +1
B Hf, +4
C Ti, +3
D Zn, +2
Slide 108 (Answer) / 113
64 An atom with the electron configuration of [Kr]5s24d2 would be in the same group as _____ and have a likely charge of ____.
A Sc, +1
B Hf, +4
C Ti, +3
D Zn, +2
[This object is a pull tab]A
nsw
er
B
Slide 109 / 113
65 Atoms on the right side of the chart tend to form negative ions because...
A Their principal energy level is almost empty
B Their principal energy level is almost full
C Their atomic number is less than other elements in that period
D Both B and C
Slide 109 (Answer) / 113
65 Atoms on the right side of the chart tend to form negative ions because...
A Their principal energy level is almost empty
B Their principal energy level is almost full
C Their atomic number is less than other elements in that period
D Both B and C
[This object is a pull tab]
Ans
wer
B
Slide 110 / 113
Let's use quantum theory to explain the trends we see amongst the charges of the transition elements.
Question 1: Elements within the Fe group can form ions of both +2 and +3 charges. Explain why the +3 charge is more common:
Question 2: Why do the elements in the zinc group tend to only form ions with a +2 charge?
Transition Metal Ions Fe = [Ar]4s23d6
The 4s electrons are readily lost yielding the +2 ion.
A half-full "d" orbital is quite stable so Fe will lose 1 d orbital electron as well to yield the +3 ion.
Slide 110 (Answer) / 113
Let's use quantum theory to explain the trends we see amongst the charges of the transition elements.
Question 1: Elements within the Fe group can form ions of both +2 and +3 charges. Explain why the +3 charge is more common:
Question 2: Why do the elements in the zinc group tend to only form ions with a +2 charge?
Transition Metal Ions
Ans
wer
2[This object is a pull tab]
Ans
wer
1
Fe = [Ar]4s23d6
The 4s electrons are readily lost yielding the +2 ion.
A half-full "d" orbital is quite stable so Fe will lose 1 d orbital electron as well to yield the +3 ion.
Slide 111 / 113
66 What is/are the possible charge(s) on a chromium ion?
Slide 112 / 113
67 What is/are the possible charge(s) on a copper ion?
Slide 113 / 113
68 What is/are the possible charge(s) on a manganese ion?