LOHS Chemistry
Periodic Trends
The objective of this activity is two fold. The first objective is to introduce Excel spreadsheets as a tool for
managing and displaying data. The second objective is to plot and interpret periodic trends of the periodic
table. You will need your periodic table and a computer with Microsoft Excel installed on the hard drive to
complete this activity.
Ultimately, you will make three plots. Most importantly, you will need to interpret their meaning.
--------------------------------------------------------------------------------------------------------------------------------------Plot 1 – Atomic radii (y-axis) vs. Atomic number (x-axis)
Enter the elements from hydrogen through xenon in column A of an Excel spreadsheet.
Enter the atomic number for each element in column B.
Enter the atomic radius for each element in column C (find these data on your periodic table).
Make an x-y scatter plot of the data form columns B and C
Include data points
Include a point to point line
Use the plot to answer to the following questions:
1) What happens to atomic radius across a period? Is this what you would expect? Explain this trend.
2) What happens to atomic radius down a group? Is this what you would expect? Explain this trend.
--------------------------------------------------------------------------------------------------------------------------------------Plot 2 – First Ionization energy vs. Atomic number
Ionization energy is the amount of energy that is needed to remove 1 electron from the valence shell of an atom.
Elements with higher ionization potential wan to hang on to their electrons more than elements with lower
ionization potentials.
Open up a new worksheet in Excel within the same workbook that you used for Plot 1.
Go back to the first worksheet and copy the first two columns of data to the new worksheet.
In column C of the new worksheet enter ionization potential data for each of the elements.
Make an x-y scatter plot for the data from columns B and C.
Include data points
Include a point to point line
Use the plot to answer to the following questions:
3) What happens to ionization potential across a period? Is this what you would expect? Explain this trend as
shown by your plot.
4) What happens to ionization potential down a group? Is this what you would expect? Explain this trend as
shown by your plot.
--------------------------------------------------------------------------------------------------------------------------------------Plot 3 – Electronegativity vs. Atomic number
Electronegativity is the affinity (amount of pull) that an atom has for electrons when bonded to another atom. It
is closely related to ionization potential, but also has some important differences.
Open up a new worksheet in Excel within the same workbook that you used for Plot 1.
Go back to the first worksheet and copy the first two columns of data to the new worksheet.
In column C of the new worksheet enter electronegativity data for each of the elements.
Make an x-y scatter plot for the data from columns B and C.
Include data points
Include a point to point line
Use the plot to answer to the following questions:
5) What happens to electronegativity across a period? Is this what you would expect? Explain this trend as
shown by your plot.
6) What happens to electronegativity down a group? Is this what you would expect? Explain this trend as
shown by your plot.
--------------------------------------------------------------------------------------------------------------------------------------Finally, copy and paste the three graphs you have made into a word document. Put all three of them on
one page. Make sure that each graph has a title and the axes labeled. Answer the questions and attach
your graph to this sheet.