113 Elements?  113 Elements?  How can we know information about so many elements????  
The Periodic Table

"My phone number is 576-4967.  Call me if you want to go fishing.  Do you need some paper to write the phone number down?" the young man asked his buddy.

"No.  I'll remember it.  I'll give you a call tomorrow," his friend replied pulling away from the parking lot. 

Psychologists tell us that the human brain is capable of remembering 7 pieces of information fairly easily.  Probably because of that reason and since for so many years people didn't know any more than 9 elements (the rest were tied up in compounds), there was no reason to categorize and classify the elements.  People could simply remember the characteristics of the individual elements without making any generalizations.  That changed quickly, though, as more and more elements were discovered.  The need for a classification system of the elements was clearly apparent.

In this unit, we are going to study the classification method people have derived.  We read a little about the history of the table in our text, more if we investigated the issue online.  We'll look at trends and information that we can interpret from the table.   We will all assume specific individual responsibilities to investigate these trends and family relationships.  We will then share with each other our findings in oral presentations.  

Qualitative data that can be interpreted from the periodic table will not be the only interpretations we will study in this unit.  We will also be studying how quantitative relationships between the elements can be read from the periodic table.  Specifically, we will look at how the table allows us to count the number of atoms of a particular substance.  In our investigations, we will uncover the concept of the mole and will also need to review the scientific notation and dimensional analysis matters.