Periodic Trends
The table that accompanies this worksheet contains a variety of information about elements in the main part of the
periodic table. Use the information in that table to create graphs to discover the trends that exist in the periodic table.
If there is a blank box for an element, it means that value has not been accurately determined or the value has no
meaning for that element. Do not include any blanks in your graph. For each problem create a graph, sketch the graph
on this paper and tell the trend that exists.
Atomic Radius
1. For members of the nitrogen family, determine the trend that exists between the period and the atomic radius.
Element
Period
Atomic
Radius
N
Phosphorus
2
3
75
110
Arsenic
4
125
Antimony
5
145
Bismuth
6
155
As you go down a column, the atomic radius increases .
2. For elements in row three, determine the trend that exists between the family and the atomic radius.
Element
Family
Atomic
Radius
Sodium
1
186
Magnesium
2
160
Aluminum
3
143
Silicon
4
118
Phosphorus
5
110
Sulfur
6
103
chlorine
7
99
As you go across a row, the atomic radius decreases.
Electronegativity
1. For members of the oxygen family, determine the relationship between the electronegativity and the period in which
the element is found.
Element
Period
Electronegativi
ty
Oxygen
2
3.5
Sulfur
3
2.6
Selenium
4
2.5
Tellurium
5
2.3
Polonium
6
1.8
As you go down a column, the electronegativity decreases.
2. For members of the third row, discover the relationship between the electronegativity and the family number of the
element.
Element
Family
Electronegativi
ty
Sodium
1
0.9
Magnesium
2
1.2
Aluminum
3
1.5
Silicon
4
1.9
Phosphorus
5
2.2
Sulfur
6
2.6
Chlorine
7
3.2
Increases
As you go across a row, the electronegativity
.
Ionization Energy
1. For the noble gases, determine the relationship between the ionization energy and the period of the element.
Element
Period
Ionization
Energy
Helium
1
24.59
Neon
2
21.57
Argon
3
15.76
Krypton
4
14
Xenon
5
12.13
Radon
6
10.75
As you go down a column, the ionization energy decreases .
2. For members of row two, discover the relationship between the ionization energy and the family number of the
element.
Element
Family
Ionization
Energy
Lithium
1
5.39
Beryllium
2
9.32
Boron
3
8.3
Carbon
4
11.26
Nitrogen
5
14.53
Oxygen
6
13.62
Fluorine
7
17.42
Neon
8
21.57
Increases
As you go across a row, the ionization energy
.
Atomic Radius vs. Ionic Radius
For elements in row three, determine the trend that exists between atomic radius and ionic radius. Draw a line for the
atomic radius vs the family number. Then draw a second line for the ionic radius vs the family number. Discuss the
trend between the two lines.
Element
Family
Atomic
Radius
Ionic Radius
Sodium
1
186
95
Magnesium
2
160
65
Aluminum
3
143
50
Silicon
4
118
41
Phosphorus
5
110
212
Sulfur
6
103
184
Chlorine
7
99
181
Discuss the trend that you observe:
For metals the atomic radius is larger than the ionic radius for nonmetals the atomic radius is smaller than the ionic
radius.