The periodic table is organized to show "periodic" traits of elements. Name at least three properties of elements in the table are traits that follow a periodic pattern.
Graphite and diamond are allotropes of the element carbon. What does this tell you about the two substances? What properties of graphite and diamond must be the same? What properties are different?
What are valence electrons? How do the number of valence electrons control the position of an element on the periodic table?