Periodic Trends – Full Lab
Purpose: to graph different information of the representative elements to look for period and group trends.
Procedure:
1. You will have 4 sections for this lab (atomic radius, ionic radius, ionization energy, and electronegativity).
2. Under each section you will have a data and a conclusion.
3. Use the provided graph paper to graph the trend vs. atomic number for periods 2-5.
Atomic Radius:
1. Use the table below to create your graph of atomic radius vs. atomic number.
Atomic Radius for Periods 2-5 in picometers
Li
128
Na
166
K
203
Rb
220
Be
96
Mg
141
Ca
176
Sr
195
B
84
Al
121
Ga
122
In
142
C
76
Si
111
Ge
120
Sn
139
N
71
P
107
As
119
Sb
139
O
66
S
105
Se
120
Te
138
2. Remember to label each atom so you can tell groups from periods.
3. Answer the following questions based on your graph.
a. Define atomic radius.
b. Comment on the sizes of the atomic radii as you go across a period.
c. Comment on the sizes of the atomic radii as you go down a group.
d. Are there any patterns (trends) that you see for periods 2-5?
e. Describe and explain the shape of each period’s portion of the graph.
f.
Are there any patterns (trends) that you see for each group?
g. Describe and explain the shape of each group’s portion of the graph.
F
57
Cl
102
Br
120
I
139
Ne
58
Ar
106
Kr
116
Xe
150
Ionic Radius:
1. Use the table below to create your graph of ionic radius vs. atomic number.
Ionic Radius for Periods 2-5 in picometers
Li
60
Na
95
K
133
Rb
148
Be
44
Mg
66
Ca
99
Sr
112
B
23
Al
51
Ga
62
In
81
C
15
Si
41
Ge
53
Sn
71
N
146
P
212
As
222
Sb
62
O
140
S
184
Se
198
Te
221
2. Remember to label each atom so you can tell groups from periods.
3. Answer the following questions based on your graph.
a. Define ionic radius.
b. Comment on the sizes of the ionic radii as you go across a period.
c. Comment on the sizes of the ionic radii as you go down a group.
d. Are there any patterns (trends) that you see for periods 2-5?
e. Describe and explain the shape of each period’s portion of the graph.
f.
Are there any patterns (trends) that you see for each group?
g. Describe and explain the shape of each group’s portion of the graph.
h. How are the radii for the anions and cations different from their atomic radius?
F
133
Cl
181
Br
196
I
220
Ne
-Ar
-Kr
-Xe
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Ionization Energy:
1. Use the table below to create your graph of ionization energy vs. atomic number.
First Ionization Energy for Periods 2-5 in kg/mol
Li
520
Na
496
K
419
Rb
403
Be
900
Mg
738
Ca
590
Sr
550
B
801
Al
578
Ga
579
In
558
C
1087
Si
787
Ge
762
Sn
709
N
1402
P
1012
As
947
Sb
834
O
1314
S
1000
Se
941
Te
869
2. Remember to label each atom so you can tell groups from periods.
3. Answer the following questions based on your graph.
a. Define first ionization energy.
b. Comment on the sizes of the ionization energy as you go across a period.
c. Comment on the sizes of the ionization energy as you go down a group.
d. Are there any patterns (trends) that you see for periods 2-5?
e. Describe and explain the shape of each period’s portion of the graph.
f.
Are there any patterns (trends) that you see for each group?
g. Describe and explain the shape of each group’s portion of the graph.
F
1681
Cl
1251
Br
1140
I
1008
Ne
2081
Ar
1521
Kr
1351
Xe
1170
Electronegativity:
1. Use the table below to create your graph of electronegativity vs. atomic number.
Electronegativity for Periods 2-5 (no units used for this)
Li
1.0
Na
0.9
K
0.8
Rb
0.8
Be
1.5
Mg
1.2
Ca
1.0
Sr
1.0
B
2.0
Al
1.5
Ga
1.6
In
1.7
C
2.5
Si
1.8
Ge
1.8
Sn
1.8
N
3.0
P
2.1
As
2.0
Sb
1.9
O
3.5
S
2.5
Se
2.4
Te
2.1
2. Remember to label each atom so you can tell groups from periods.
3. Answer the following questions based on your graph.
a. Define electronegativity.
b. Comment on the sizes of the electronegativity as you go across a period.
c. Comment on the sizes of the electronegativity as you go down a group.
d. Are there any patterns (trends) that you see for periods 2-5?
e. Describe and explain the shape of each period’s portion of the graph.
f.
Are there any patterns (trends) that you see for each group?
g. Describe and explain the shape of each group’s portion of the graph.
F
4.0
Cl
3.0
Br
2.8
I
2.5
Ne
-Ar
-Kr
-Xe
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