In this lab, we'll dig into trends within the periodic table such as ionic radius, ionization energy, electronegativity, and electron affinity.
The first thing we need to do is find a reliable and informative periodic table that contains all of the properties we mentioned above. There's an example here.
Pick any two rows and two columns of the periodic table. For each element in the rows and columns, record the atomic number, ionic radius, ionization energy, electronegativity, and electron affinity.
Now find a computer with a graphing program. Or if you prefer old school methods, use graphing paper. Don't worry—we won't judge you for using graphing paper.
For each of the elemental properties plot the atomic number (Z) on the x-axis and the property on the y-axis. Each property should be graphed on a separate sheet of paper. It might also help to graph the elements of each column or row in a different color to help you visualize the results.
Once you're done, it's time to dive right in and answer the following:
1. What do we mean by periodic trends?
2. Based on your graphs, what is the trend in atomic radius across a period? Down a family?
3. Based on your graphs, what is the trend in ionization energy across a period? Down a family?
4. Based on your graphs, what is the trend in electronegativity across a period? Down a family?
5. What can you deduce about the relationship between ionization energy and reactivity of metals?
6. What can you deduce about the relationship between electron affinity and the reactivity of nonmetals?
In this “experiment” we'll be watching a movie, gossiping, playing Sherlock, and learning about an element. This is our kind of lab.
Arsenic and Old Lace is a play written in 1941 by Joseph Kesselring. It was also turned into a film starring Cary Grant in 1944. It's the story of two elderly sisters who poison unsuspecting boarders by serving them wine that just happens to have arsenic added to it.
Your task is simple. Watch the movie. Or read the play. It's your choice. Once you've completed the film and finished your popcorn, answer the following questions.
Pretend you're a modern day investigative reporter. Consider the following:
What is arsenic?
How does it affect the body?
Have any historical figures died from arsenic poising?
Are there any cases of arsenic poisoning today?
What about the environmental concerns about arsenic?
You might find these websites helpful as you are completing your investigation:
Once these tasks are complete, write up a nice summary (2 – 3 pages) of your findings.