Download periodic table trends assignment 2013 billo

SCH3U Matter, Chemical Trends and Bonding
Trends in the Periodic Table
In this exercise, you will construct three different graphs to obtain a pictorial
representation of the changes in three properties of the elements as their atomic number
increases. By plotting these properties, you should see that elements are grouped within
the periodic table according to similarities in these properties. The three properties are
atomic radius, ionization energy, and electronegativity.
Atomic Radius
The atomic radius of an atom is the distance from the centre of the atom to the outermost
shell that contains electrons. A convenient unit for this distance is the picometer, which is
one/one trillionth of a meter (1 x 10-9 m).
Ionization Energy
The ionization energy of an atom is the amount of energy (in kilojoules) that is required to
remove one of the outermost electrons from the atom. In other words, the energy needed
to strip an electron away from the atom.
Electronegativity
The electronegativity of an atom is a measure of the ability of the atom to attract an
electron from another atom. If an atom is really good at ‘stealing’ electrons from another
atom, then it has a high electronegativity value. The Noble Gas elements do not have
electronegativity values since they are stable with full outer energy levels.
Procedure: For each set of data...
1. Turn the graph paper sideways so that the long side becomes the X-axis. The X-axis
is the Atomic Number for all graphs and should take up the whole side of the paper.
2. Label the Y-axis with the given property and establish a scale that begins with ‘0’.
3. Graph the data below.
4. Label each point with the corresponding element symbol.
5. At atomic numbers 2(He), 10(Ne) and 18(Ar) draw a red vertical line through the
graph. This separates the plot into four sections. Label the sections 1 – 4.
6. In each section, draw a curve of best fit among the points. DO NOT play connect
the dots!!
7. Include a title.
Atomic Radius for the First 20 Elements
Atomic Number
1
2
3
4
5
6
7
8
9
10
Atomic Radius
(picometers)
37
32
152
111
79
77
74
76
71
69
Atomic Number
11
12
13
14
15
16
17
18
19
20
Atomic Radius
(picometers)
186
160
143
117
110
102
100
97
227
197
Ionization Energy for the First 20 Elements
Atomic Number
1
2
3
4
5
6
7
8
9
10
Ionization Energy
(kJ/mol)
1294
2336
511
886
787
1071
1380
1294
1656
2048
Atomic Number
11
12
13
14
15
16
17
18
19
20
Ionization Energy
(kJ/mol)
486
725
569
775
1046
985
1236
1496
408
581
Electronegativity Values for the First 20 Elements
Atomic Number
1
2
3
4
5
6
7
8
9
10
Electronegativity
2.1
No Value
1.0
1.5
2.0
2.5
3.0
3.5
4.0
No Value
Atomic Number
11
12
13
14
15
16
17
18
19
20
Electronegativity
0.9
1.2
1.5
1.8
2.1
2.5
3.0
No Value
0.8
1.0
Questions - Please answer with complete sentences.
Atomic Radius
1. According to the graph, what happens to the radius (size) of an atom as you move
across a Period (row) of the Periodic Table?
2. According to the graph, what happens to the radius (size) of an atom as you move
down a Group (column) of the Periodic Table?
Ionization Energy
1. Generally, what happens to the ionization energy of an atom as you move across a
Period of the Periodic Table?
2. Generally, what happens to the ionization energy of an atom as you move down a
Group of the Periodic Table?
3. How are these trends different that those seen for Atomic Radius?
Electronegativity
1. Generally, what happens to the electronegativity of an atom as you move across a
Period?
2. Generally, what happens to the elctronegativity of an atom as you move down a
Group?
3. How are these trends different that those seen for Atomic Radius?