Notes: Periodic Trends
Periodic Trends: Atomic Radius
EXPLORE: Look at the periodic table at your desk. Talk to a partner about this chart and make a
prediction about what information it is conveying. Write all observations and predictions below.
1. Define Atomic Radius:
2. Atomic radius is usually measured in what unit?
3. Using the Trends in Atomic Radius chart at your desk determine the atomic radius of
each of the following atoms
Atom
Atomic Radius
Helium
Nitrogen
Bismuth
Cesium
4. Describe the atomic radius trends in the periodic table below
Vertically down Columns
Horizontally across Rows
Trend
Explanation
Introduction to Chemistry
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Notes: Periodic Trends
Animation explaining atomic radius trend (linked in power point):
5. What happens during the formation of the ion pair? Descirbe what happens to the
electrons and atomic radii of Li and F atoms as they ionically bond.
6. Describe what is happening to the atomic radius as the atomic number increases in an
isoelectronic series.
7. Which has the larger atomic radii Fe2+ or Fe3+? Explain.
8. Explain what is meant by shielding and what effect does it have on the outermost
electrons? Draw an example of a shielded atom – you can use the Borh model you
learned in middle school.
Periodic trends: Ionization energy
Define:
9. Photon
10. Ionization
11. ionization energy
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Notes: Periodic Trends
12. Draw a diagram representing ionization. (Follow my lead on the board) (Endothermic)
13. The larger the atom is the _____________ energy is needed to ionize the atom.
14. As the atomic radius increases the ionization energy ___________________, we say that
the atomic radius is _____________________ proportional to the ionization energy.
Observe the table below
15. What is the independent variable? _____________________________
16. What is the dependent variable? _____________________________
17. What is the ionization energy of helium?
18. What is the ionization energy of carbon?
19. What is the ionization energy of neon?
20. What is the ionization energy of iodine?
21. Describe the general trend in the ionization energy as the atomic number increases
Introduction to Chemistry
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Notes: Periodic Trends
Use the blank periodic table below to represent the overall trend in ionization energy.
22. Which element has the highest ionization energy? Explain why.
23. Which element has the lowest ionization energy? Explain why.
Introduction to Chemistry
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Notes: Periodic Trends
Periodic Trends: Electron Affinity
What does the word affinity mean to you?
Define:
1. Electron affinity
2. When an atom gains an electron it can be ___________________ or ________________
Endothermic
Exothermic
3. Use the periodic table below to represent the electron affinity trend in the periodic
table.
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Notes: Periodic Trends
Periodic trend: Metallic character
Define: Metallic character
Use the table below to represent the trend in how easily electrons are given up.
Periodic Trends: Electronegativity
Definition
Introduction to Chemistry
Scale
Units of
measure
Examples of elements
with low
electronegativies
Examples of
elements with low
electronegativies
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Notes: Periodic Trends
Use the table below to represent the periodic trend for electronegativity
Define:
The Octet Rule -
Cations
Introduction to Chemistry
Anions
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Notes: Periodic Trends
Notes:
Introduction to Chemistry
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