Purpose:
- To learn how to use graph paper, and computer programs in order to create graphs efficiently for the lab notebooks and other assignments.

- To identify trends on the Periodic Table by constructing graphs to correspond with the trends

Task:
In this activity you will be asked to create several graphs using Microsoft Excel and at least one by hand.  Often times in class or at home the computers are available for you, but sometimes (especially during tests) you have to draw graphs by hand.  It is important that you know how to do both.

Assignment:
You will create graphs using Microsoft Excel and print them for your teacher. You will also have to complete one graph on graph paper to be submitted with the printed graphs. For each of the graphs there will be some questions that will need to be answered.

Scoring:
Computer graphs are worth 5 points each, the hand drawn graph is worth 10 and each question is worth 2 points.

Instructions:
Read through the following notes on hand drawn and Excel graphing and create the graphs as instructed in the "Activity" section below. You may print the notes if you wish so that you may use them as a reference later.

Notes:

Hand Drawn Graph "Rules"

• Always use at least ¾ of the graph space provided
• Always title the graph
• Always label both axis WITH UNITS
• Provide a key when necessary
• The Independent Variable (the one controlled by the scientist) will go on the X-axis (horizontal).
• The Dependent Variable (directly affected by the other variable) goes on the Y-axis (vertical).

Spacing and Numbering

In order to ensure that ¾ of the graph space is used, follow these steps:

1. Determine the range for each axis. To do this, take the largest value in your data and subtract the smallest (which may often be zero, but does not always need to be).
2. Count the number of lines (squares) available along the desired axis.
3. Divide the number of lines by the range in the following equation:
   

   
4. If you get a decimal, then ROUND UP to a reasonable increment (whole number, nearest 0.5, 0.1 or whatever you may need for the data range) and label the graph with that value for each line.

Graphing with Excel

• Add data to two columns on the spreadsheet with the numbers you want on the X-axis listed in the FIRST column.
• Highlight the NUMBERS for the columns
• Click on the "Chart Wizard" button.

See the Red Arrows in the picture below for help:

• Click on the "Scatter Plot" and then the"Next" buttons as indicated with the red Arrows in the following picture:

• Click the "Next" button several times until the following page appears. Provide the title and the labels for each axis, INCLUDING UNITS. Then hit the "Next" button again.

• Click "As a New Sheet" and then "Finish. ...You're done...Nice Work. Now follow the directions for adding a Trendline if a line is needed. The following picture is the last two commands.

To add a Trendline (if needed)

• Once the graph is created, right click once on any data point.
• Go to "Add Trendline" and click.
• Click on the "Options" tab.
• Highlight the "display equation on graph" button and the "display R-squared value" button.
• Click "OK"

See the picture below for the trendline commands:

Click on the following link to get the PowerPoint version of the notes above so that it is more printer friendly. The printable version uses FlashPaper and may require you to allow pop-ups.

Activity:
You may copy and paste this section or click to get a printer friendly section copy of the following information.

Name _________________________________ Period _________ Date _______________________

Graphing Trends in the Periodic Table

Student outcome: The student will graph and explain the trends found on the Periodic Table.

Problem: Are certain properties of elements periodic of their atomic numbers?

Materials: graph paper, computer with Microsoft Excel, possibly colored pencils.

Procedures:
In this activity you will be making 4 graphs. The first will be done on graph paper (hand drawn) while the rest will be done using Excel. Each graph will use the data found in the section of the Periodic Table that is found below. Trendlines are not necessary for these graphs, but you should connect the data points with lines.

To connect the cata coints with a continuous line:

• Right click on any data point
• Choose "Format Data series"
• In the box labeled "Line" choose and click on the space for "Automatic" then click "OK"

Graph 1: For elements 3-20, use the data below to graph atomic radius as a function of atomic number. Plot atomic number on the X-axis (as it will throughout the activity on all of the graphs) and atomic radius on the Y-axis. Be sure to properly space the graph and label all aspects accordingly. This one is to be done on graph paper (provided to you in class).

Graph 2: Use Excel to create and print a graph of atomic radius as a function of atomic number for the elements in Column 1 on the table.
Follow the directions below to add a second line for Column 2 from the table.

Special notes on how to add data to existing graph:

• Go back to the spreadsheet page that had your original data. Create the columns containing data for the information you wish to add (new columns or add data to the bottom of the existing columns - leaving one row blank between them so that you are not confused later).
• Go back to the graph, and Right click anywhere in the graph area. Choose "Source Data" from the list of options and click on it.
• Open the "Series" tab and you will see your existing data linked to the spreadsheet page and labeled "Series 1".
• Click the "add" button and "Series 2" will appear. Highlight the box labeled "Values" and then click on the button to the right that looks like a spreadsheet page. This will allow you to go back to your spreadsheet where you can highlight the data for the Y-axis and then close the spreadsheet button again to go back to the previous page. You have just instructed the computer to include those values for Y.
• Towards the bottom of the page, there is "Category (X) axis labels" where you can repeat the procedure you just followed for the Y-axis and link to the values for the X-axis as you did a moment ago for Y.
• While the "Series 2" is still highlighted, type into the "Name" box Alkaline Earth Metals as you are naming column 2 of the table according.
• Click once on "Series 1" and rename it Alkali Metals in the "Name" box.
• Click "OK" at the bottom of the page.

Graph 3: For elements 3-20, use Excel to create and print a graph of the energy required to remove the easiest electron (ionization energy) as a function of atomic number.

Graph 4: Use Excel to plot and print a graph of ionization energy as a function of atomic number for the elements in Column 1 of the table.
Repeat the procedure above to include a second line for the elements in Column 2.

Observations:

Conclusions: Use your text or notes from class to answer the following questions.