Download Atomic Radius File - Galena Park ISD Moodle

Name ______________________________________________
Chemistry
Analyzing Trends in Data – Atomic Radius
Date ____________
Period __________
Introduction
Mendeleev noticed that when the elements were arranged in order of
increasing mass, chemical properties repeated periodically. This periodicity
was the first observation leading to the organization of the Periodic Table of
the Elements. Following Mendeleev, Moseley showed that periodicity was
related to atomic number rather than mass. As a result, the elements in the
modern periodic table are arranged in order of increasing atomic number.
In this laboratory investigation, you will select the appropriate data
and then analyze the information to determine the group and period trends
for atomic radius, first ionization energy and electronegativity.
Problem:
Which properties of elements are repeated periodically?
Procedures:
Analyze data in tables, charts and/or graphs to describe periodic trends.
Prepare charts and/or graphs using the data on the periodic table.
Complete the data chart for the following elements.
Symbol
Atomic Number
Number of
Protons
19
Li
Rb
11
55
Complete the data chart for the elements.
Symbol
Atomic Number
Number of
Electrons
Ne
8
6
4
F
3
7
B
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Atomic Radius
(picometers)
227
152
244
186
262
Atomic Radius
(picometers)
70
66
77
112
64
152
71
80
Name ______________________________________________
Chemistry
Analyzing Trends in Data – Atomic Radius
Date ____________
Period __________
Atomic Radius = half the distance between the nuclei of identical atoms
Prepare one graph that includes two data lines. Use a different colored
pencil for each graph line. Complete the key for your graph that indicates
the category for each data line. Do not forget to label your axis. Atomic
Number is the independent variable. Plot the graphs for:
Group I - Atomic Radius versus Atomic Number
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KEY
Name ______________________________________________
Chemistry
Analyzing Trends in Data – Atomic Radius
Date ____________
Period __________
KEY
Period 2 – Atomic Radius versus Atomic Number
Discussion Questions: Your answers for questions 1 & 2 must be in
complete sentences.
1.
Based on your graph, what is the relationship between atomic number
and atomic radius in group 1? Explain this trend using your knowledge of
the Bohr atom.
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Name ______________________________________________
Chemistry
Analyzing Trends in Data – Atomic Radius
Date ____________
Period __________
2.
Based on your graph, what trend do you observe between the atomic
number and the atomic radius in period 2? Explain this trend using your
knowledge of the Bohr atom.
3.
An example of an atom with an atomic radius smaller than that of Sulfur
(S) is __________.
A.
B.
C.
D.
E.
4.
Oxygen (O)
Chlorine (Cl)
Calcium (Ca)
Lithium (Li)
None of the above
Nitrogen has a larger atomic radius than Oxygen.
A. True
B. False
5.
Identify the largest of each pair listed below and explain why that one is
larger.
A. oxygen or sulfur
B. calcium or potassium
C. nitrogen or oxygen
D. copper or gold
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