Download Periodic Trends

IST9 Honors Option: Periodic Table - Graphing Periodic Trends
Name___________________________per____
PURPOSE: To determine how certain properties are periodic when the elements are arranged in periods or
groups.
MATERIALS: graph paper.
DISCUSSION: There are many periodic trends that occur as you cross a period or go down a family on the
Periodic Table. For example, as you go across a period the elements generally increase in atomic mass and
become less metallic. As you go down a family (group) both the atomic mass and atomic number increase.
REFERENCE:
Angstrom - A unit of distance equal to one ten-billionth of a meter (1 x 10ee-10 meter).
Atomic Radius - The distance from the center of the nucleus to the valence electron energy level.
Ionization energy - the energy required to remove an electron from an atom.
Valence electrons - the electrons that occupy the outside energy level in an atom.
DATA:
Using the data above, make 2 line graphs as listed below. On each graph, draw a dark vertical line to
separate the 3 periods. Important: Connect your points since the data is extremely accurate.
1. Atomic Radius (y) vs. Atomic Number (x) for the first 3 periods (18 elements).*
2. Ionization energy (y) vs. Atomic Number (x) for the first 3 periods (18 elements).*
*Important: Label each point with the chemical symbol and draw vertical lines on your graph paper to show
periods 1, 2 and 3.
Use your graphs to answer these Conclusion questions in complete sentences on separate paper:
1. What happens to the atomic radius as you go across a period?
2. What happens to the atomic radius as you go down a group?
3. What happens to the energy required to remove an electron as you go across a period?
4. What happens to the energy required to remove an electron as you go down a group?
5. What is the relationship between Atomic Radius and Ionization Energy?
6. Based on the trend of the graphs, which element on the Periodic Table would you predict to have the
largest Atomic Radius?
7. Based on the trend of the graphs, which element on the Periodic Table would you predict to be the hardest
to remove an electron from?
8. Based on the trend of the graphs, which element on the Periodic Table would you predict to be the easiest
to remove an electron from?