I had students define vocab from one section of our text in their own words, then had them find groups of words and identify the connection among them with hash tags (ala twitter). For example: solid, liquid gas, plasma #statesofmatter. This worked best when I told the students that there were four easy groups, and challenged them to find two more. In review, I asked random studemts for the four easy ones, and volunteers for the more challenging ones.
This is a good way to introduce vocabulary that you’ll be using during a unit.