name: _______________
date: _______
periodic trends - atomic radius and ionic radius
atomic radius versus atomic number
The radius of atoms is both measurable and predictable. It depends on both the number of occupied energy levels
and the strength of attraction that the nucleus has for its electrons. Since electrons have a negative charge, they repel each
other, but since protons have a positive charge, there is an attraction of the electrons toward the nucleus.
Using this information, predict what will happen to the size (radius) of atoms as you:
• move across a period from left to right?
_____________________________
• move down a group?
_____________________________
Using the data in the chart, make a line graph of the atomic radius vs. the atomic number. Then follow the directions below
for annotating the graph. The unit for atomic radius is nanometers, or 1 x 10-9 meters.
A. N.
radius
A. N.
radius
A. N.
radius
A. N.
radius
A. N.
radius
A. N.
radius
1
0.030
10
0.093
19
0.152
28
0.111
37
0.088
46
0.077
2
0.070
11
0.066
20
0.064
29
0.112
38
0.186
47
0.160
3
0.143
12
0.117
21
0.110
30
0.104
39
0.099
48
154
4
0.231
13
0.197
22
0.160
31
0.146
40
0.131
49
0.125
5
0.129
14
0.126
23
0.125
32
0.124
41
0.128
50
0.133
6
0.122
15
0.122
24
0.121
33
0.117
42
0.114
51
0.169
7
0.244
16
0.215
25
0.180
34
0.157
43
0.143
52
0.136
8
0.137
17
0.133
26
0.134
35
0.138
44
0.144
53
0.149
9
0.162
18
0.140
27
0.141
36
0.137
45
0.133
54
0.190
ionization energy versus atomic number
Ions are formed form by the loss or gain of electrons. Ionization energy is the energy required to remove the most
loosely held valence electron from the atom to make the atom a +1 ion. The following table has the ionization energies of the
first 54 elements. Using the data in the chart, make a line graph of the ionization energy vs. the atomic number. Ionization
energy is measured in kilojoules, or kJ.
A. N.
IE
A. N.
IE
A. N.
IE
A. N.
IE
A. N.
IE
A. N.
IE
1
13.5
10
24.5
19
5.4
28
9.3
37
8.3
46
11.2
2
14.5
11
13.6
20
17.3
29
21.5
38
5.1
47
7.6
3
6.0
12
8.1
21
11.0
30
10.4
39
13.0
48
15.8
4
4.4
13
6.1
22
6.6
31
6.8
40
6.7
49
6.8
5
7.4
14
7.9
23
7.9
32
7.6
41
7.7
50
9.4
6
6.0
15
8.1
24
10.5
33
9.7
42
11.8
51
14.0
7
4.2
16
5.7
25
6.6
34
7.0
43
6.8
52
7.2
8
7.3
17
7.5
26
7.7
35
8.3
44
7.6
53
9.0
9
5.8
18
7.3
27
8.6
36
9.0
45
10.4
54
12.1
graph annotation:
On the atomic radius versus atomic number graph, do the following:
a. Label the points on the graph that represent an element with a valence configuration of ns1 (1 valence e-).
b.Label the points on the graph that represent an element with a valence configuration of ns2np6 (8 valence e-)
c. Circle the points on the graph that represent the 3d sublevel and the 4d sublevel. d. Draw a vertical line through the points on the graph that represent a filled valence shell. questions:
1. How many sections was the atomic radius graph divided into? _____
2. On the periodic table, the first 54 elements are found in 5 horizontal rows known as __________.
3. Each section of the graph represents a __________ or horizontal row on the periodic table.
4. What is the trend in atomic radius within each section of the graph (how does atomic radius change with atomic number)?
5. As you move across a period on the periodic table, what happens to the atomic radius of the elements?
6. Are electrons being added to higher energy levels as you move from left to right across a period? Or, are they being
added to the same energy level? What is responsible for the decrease in atomic radius across a period?
7. List the atomic numbers of the largest atom in each section of the graph. In what group on the periodic table are each of
these elements located?
8. List the atomic numbers of the smallest atom in each section of the graph. In what group on the periodic table are each
of these elements located?
On the ionization energy versus atomic number graph, do the following:
a. Label the points on the graph that represent an element with a valence configuration of ns1 (1 valence e-).
b.Label the points on the graph that represent an element with a valence configuration of ns2np6 (8 valence e-)
c. Circle the points on the graph that represent the 3d sublevel and the 4d sublevel. d. Draw a vertical line through the points on the graph that represent a filled valence shell. questions:
1. Define ionization energy.
2. Each section of the graph represents a __________ or horizontal row on the periodic table.
3. State the general trend in ionization energy moving across a period.
4. List the atomic number of the elements that have the lowest ionization energy in each section of the graph.
5. To what group of the periodic table do these elements belong?
6. List the atomic number of the elements that have the highest ionization energy in each section of the graph.
7. To what group of the periodic table do these elements belong?
name: suggested answers
date: _______
periodic trends - atomic radius and ionic radius
atomic radius versus atomic number
The radius of atoms is both measurable and predictable. It depends on both the number of occupied energy levels
and the strength of attraction that the nucleus has for its electrons. Since electrons have a negative charge, they repel each
other, but since protons have a positive charge, there is an attraction of the electrons toward the nucleus.
Using this information, predict what will happen to the size (radius) of atoms as you:
• move across a period from left to right?
atomic radius decreases
• move down a group?
atomic radius increases
Using the data in the chart, make a line graph of the atomic radius vs. the atomic number. Then follow the directions below
for annotating the graph. The unit for atomic radius is nanometers, or 1 x 10-9 meters.
A. N.
radius
A. N.
radius
A. N.
radius
A. N.
radius
A. N.
radius
A. N.
radius
1
0.030
2
0.093
3
0.152
4
0.111
5
0.088
6
0.077
7
0.070
8
0.066
9
0.064
10
0.062
11
0.186
12
0.160
13
0.143
14
0.117
15
0.110
16
0.104
17
0.099
18
0.095
19
0.231
20
0.197
21
0.160
22
0.146
23
0.131
24
0.125
25
0.129
26
0.126
27
0.125
28
0.124
29
0.128
30
0.133
31
0.122
32
0.122
33
0.121
34
0.117
35
0.114
36
0.112
37
0.244
38
0.215
39
0.180
40
0.157
41
0.143
42
0.136
43
0.137
44
0.133
45
0.134
46
0.138
47
0.144
48
0.149
49
0.162
50
0.140
51
0.141
52
0.137
53
0.133
54
0.130
ionization energy versus atomic number
Ions are formed form by the loss or gain of electrons. Ionization energy is the energy required to remove the most
loosely held valence electron from the atom to make the atom a +1 ion. The following table has the ionization energies of the
first 54 elements. Using the data in the chart, make a line graph of the ionization energy vs. the atomic number. Ionization
energy is measured in kilojoules, or kJ.
A. N.
IE
A. N.
IE
A. N.
IE
A. N.
IE
A. N.
IE
A. N.
IE
1
13.5
2
24.5
3
5.4
4
9.3
5
8.3
6
11.2
7
14.5
8
13.6
9
17.3
10
21.5
11
5.1
12
7.6
13
6.0
14
8.1
15
11.0
16
10.4
17
13.0
18
15.8
19
4.4
20
6.1
21
6.6
22
6.8
23
6.7
24
6.8
25
7.4
26
7.9
27
7.9
28
7.6
29
7.7
30
9.4
31
6.0
32
8.1
33
10.5
34
9.7
35
11.8
36
14.0
37
4.2
38
5.7
39
6.6
40
7.0
41
6.8
42
7.2
43
7.3
44
7.5
45
7.7
46
8.3
47
7.6
48
9.0
49
5.8
50
7.3
51
8.6
52
9.0
53
10.4
54
12.1
graph annotation:
On the atomic radius versus atomic number graph, do the following:
a. Label the points on the graph that represent an element with a valence configuration of ns1 (1 valence e-).
b.Label the points on the graph that represent an element with a valence configuration of ns2np6 (8 valence e-)
c. Circle the points on the graph that represent the 3d sublevel and the 4d sublevel. 1st period
d. Draw a vertical line through the points on the graph that represent a filled valence shell.
2nd period
3rd period
5th period
4th period
Rb
K
Na
4d sublevel
Li
3d sublevel
Xe
Kr
Ar
Ne
questions:
1. How many sections was the atomic radius graph divided into? 5 sections
2. On the periodic table, the first 54 elements are found in 5 horizontal rows known as periods.
3. Each section of the graph represents a period or horizontal row on the periodic table.
4. What is the trend in atomic radius within each section of the graph (how does atomic radius change with atomic number)?
atomic radius decreases
5. As you move across a period on the periodic table, what happens to the atomic radius of the elements?
atomic radius decreases across a period, form left to right
6. Are electrons being added to higher energy levels as you move from left to right across a period? Or, are they being
added to the same energy level? What is responsible for the decrease in atomic radius across a period?
across a period, electrons are added to the same energy level; number of protons in the nucleus affects the radius
7. List the atomic numbers of the largest atom of each section of the graph. In what group on the periodic table are each of
these elements located?
3, 11, 19, 37; located in group 1 (alkali metals) on the periodic table
8. List the atomic numbers of the smallest atom of each section of the graph. In what group on the periodic table are each
of these elements located?
3, 11, 19, 37; located in group 1 (alkali metals) on the periodic table
On the ionization energy versus atomic number graph, do the following:
a. Label the points on the graph that represent an element with a valence configuration of ns1 (1 valence e-).
b.Label the points on the graph that represent an element with a valence configuration of ns2np6 (8 valence e-)
c. Circle the points on the graph that represent the 3d sublevel and the 4d sublevel. d. Draw a vertical line through the points on the graph that represent a filled valence shell.
2nd period
3rd period
4th period
5th period
He
Ne
Ar
Kr
Xe
1st period
H
Li
Na
K
Rb
questions:
1. Define ionization energy.
the energy needed to remove an electron from an atom to form a +1 ion
2. Each section of the graph represents a period or horizontal row on the periodic table.
3. State the general trend in ionization energy moving across a period.
ionization energy increases across a period from left to right
4. List the atomic number of the elements that have the lowest ionization energy in each section of the graph.
3, 11, 19, 37
5. To what group of the periodic table do these elements belong?
the alkali metals
6. List the atomic number of the elements that have the highest ionization energy in each section of the graph.
2, 10, 18, 36, 54
7. To what group of the periodic table do these elements belong?
the noble gases