Atomic Radius and Ionization Energy
Nick DiPreta
Jonny Masci
Due Date: 12/23/09
Atomic Radius Tabulation
A. List the symbols and atomic numbers of the elements through which the red lines pass.
B. The symbols and atomic numbers of the elements with the smallest atomic radius in each section of your graph.
C. The symbols and atomic numbers of the elements with the largest atomic radius in each section of your graph.
A.
B.
C.
Symbol/Atomic #
Symbol/Atomic #
Symbol/Atomic #
He-2
Section 1= 1-H
Section1= H
Ne-10
Section 2= 9-F
Section2= 3-Li
Ar-18
Section3= 17-Cl
Section 3= 11-Na
Kr-36
Section 4= 35-Br
Section 4=19-K
Xe-54
Section 5= 53-I
Section 5=37-Rb
A)
21(Sc), 22 (Ti), 23(V), 24 (Cr), 25 (Mn), 26 (Fe), 27 (Co), 28 (Ni), 29 (Cu), 30 (Zn)
B)
39 (Y), 40 (Zr), 41 (Nb), 42 (Mo), 43 (Tc), 44 (Ru), 45 (Rh), 46 (Pd), 47 (Ag), 48 (Cd)
Questions
1) Note the regular, repeating pattern in each section of the graph. How can you explain this pattern? Call
upon your knowledge of electron configurations.
The alkali metal of each period is the highest point in each section for atomic radius, then it decreases on a
curve as the atomic numbers increase, then jumps back up again when it reaches the next alkali metal period. This is
because as the number of protons increases, the electrons get pulled tighter into the center of the atom.
2) What can you say about the trend in atomic radius as the atomic number increases within a vertical
column?
The atomic radius on the periodic table of elements increases within a vertical column going from top to
bottom due to the increased number of electrons, making the valence electrons in farther out shells.
3) What can you say about the trend in atomic radius as the atomic number increases within each section of
the graph? Give a reason for this trend
The atomic radius gradually increases from section to section of the graph. This is due to the fact that as atomic
number increases, the number of layers or principle energy levels increases, increasing the atomic radius. The
atomic radius decreases as the atomic number increases within each section of the graph, because the same principle
energy level is being filled. Because there are more protons, the electrons become pulled towards the nucleus as the
atomic numbers go up until it reaches the next period at which point the radius gets suddenly larger. This is a direct
cause of the jump that we see between layers.
4) What can you say about the trend in atomic radius as the atomic number increases while d orbitals are
filling? Give a reason for this trend.
The atomic radius is continually decreasing as the d orbitals are filling, because as the number of electrons
increases, so does the number of protons, hence, pulling them in closer.
Ionization Tabulation
a.the highest ionization energy in each section of the graph
b. the lowest ionization energy in each section of the graph
c. the next-to-highest ionization energy in each section of the graph
a.
b.
c.
2 He
3 Li
1H
10 Ne
11 Na
9F
18 Ar
19 K
17 Cl
36 Kr
37 Rb
5 Br
54 Xe
53 I
Conclusions:
1.
Describe the pattern formed by your graph.
The noble gases have the highest ionization energy, then the graph drops to the alkali metals, and gradually
increases until it reaches the next noble gas.
2.
How can you explain the pattern? (includes the explanation from the second 3)
The noble gases have the highest ionization energy because they don't want to gain any electrons because
their valence is full, thus they are most stable as is. The alkali metals want to lose an electron because they only have
one electron in their valence and would be more stable in an ionic state, which is why they so readily bond. The
alkali earth metals want to lose two to become more stable, but this is harder than just losing one so the ionization
energy goes up. This continues all the way up until the next noble gas, each consecutive element is more difficult to
lose an electron than the last because each has more electrons in the valence than the previous.
3.
What can you say about the effect of atomic number on ionization energy within a vertical column? Within
a section of the graph (energy level)?
As the atomic number increases in a vertical column, the ionization energy decreases. Within a period, the
ionization energy increases.
Periodic Table Game
1
2
13
14
15
16
17
18
1
F
X
2
S
H
D
U
M
A
V
B
3
I
T
Z
G
C
Q
O
E
4
P
L
R
N
Y
K
W
Conclusion
Several conclusions can be drawn from this lab. Firstly, that we can see trends in data when plotted on a line graph,
like the graphs we made. By looking at the numbers alone, one would never have been able to see the trends that
become obvious when plotted. By using the background knowledge we had, we made inferences about the data and
atomic radius and ionization energy that we couldn’t have made before we graphed. Thus, it becomes obvious that
graphing is a very useful tool when analyzing data, as it produces it in a more visual and spatial manner.