1. Light up the Sky!
Can you list and briefly describe the important elements that make a firework work? Go to the following links and then compile that list.

Consider This Before Answering the Questions Are you one of those individuals who, as a kid, "oohed and ahed" over fantastic fireworks that seemed to get ever more spectacular each year? Of course, most of us know that it was the ancient Chinese who first invented these remarkable exhibitions (as well as gun powder), but do you know what the components are that go into their beautiful showers of light?

• Go to http://www.pbs.org/wgbh/nova/kaboom/elemental to explore the periodic table of elements to see what role different elements play in these exciting displays.
• Click on the elements that are highlighted and record the role of each in fireworks displays.

After You Answer the Questions
If you're interested, you can put together your own combination of elements too and describe what you'd expect to see.

2. Everything You've Ever Wanted to Know about the Periodic Table of Elements
What is a "neutral" atom is and what happens when the number of electrons changes? How is the periodic table built up? What do the letters "s," "p," and "d" mean? How would you explain the rules for electron configurations? What are the origins of the periodic table? Have you ever thought about how you could possibly "weigh" an atom? How did they arrive at the name "periodic table"?

To answer these questions, follow the links at below.

Consider This Before Answering the Questions
This is a truly long exercise so you may want to work at it over two or three days; however, by the time you're through you should have an intimate understanding of the various atoms that comprise our universe.

• Start out by going to the following web site http://www.colorado.edu/physics/2000/elements_as_atoms/index.html.
• As you move from "Elements as Atoms" to "Beyond the Hydrogen Atom" close the pop-up of "David's Whizzy Periodic Table" and instead link to the "Periodic Table Applet" (same thing, just the applet opens much more quickly).
• As you proceed through the lesson, you'll come to that applet several times-each time a bit more gets added, so keep looking and exploring and clicking on different elements to see what happens.

You've already explored the hydrogen atom in the last chapter, but we'll move on from there in this exercise. Try to answer the questions before the "professor" gives his explanation, then check to see if you were correct.

• In the session on "Electron Configurations and the Periodic Table II," click to open the extended version of the table and do as the professor instructs, "play around with this and figure out the order in which the various orbitals are filled."
• The next section provides a preview for you of material in Chapter 12, but it's a small section, so you may want to look through it, then move on to the discussion of "The Origin of the Periodic Table." Here you should take a small side trip by linking to atomic weight, so you understand how that is derived (have you ever thought about how you could possibly "weigh" an atom?).
• Clicking on the "Previous" link, scroll down to "Next" so you can move on to "Periodic Properties" and find out how did they arrive at the name "periodic table"?

After You Answer the Questions
You'll notice that the next section on the site, "Atomic Structure and Chemical Properties," also relates to Chapter 12, but it's easier to move through it than to skip around-it's really easy to get lost here!

• As you move on, see how well you can explain "transition metals."
• How do they differ from the other elements?
• Why are the transition metals so "weird"? (What does the professor say?)
• Continue through the "Electron Configurations and the Periodic Table II," clicking on the various elements described to see what happens and then look at the extended version of the periodic table showing configurations of elements up to 103. What are lanthanides and actinides?
• Your final assignment here is "The Structure of the Periodic Table": Is there more to discuss? Is this the end, or do you think more will be discovered? Who knows-if you discover one in your career, it may end up with your name!