The White Powder Activity

What are we doing to help kids achieve and learn?

      I always feel a need to start the year off with an activity that ties in observations and conclusions but I also know that most students have had that in science classes since the early grades. Is there a way to revisit an old topic with a new or more challenging bent?

     Students walk in the room and are presented with a small cup with a white powder. They are told to observe the entire system. They are encouraged to record as much data as possible and are told the data will be used at a later date. They are also allowed to add water and stir should they so choose. Here is what they are not always prepared for...

     Two days later they come in and they find that there are three powders labeled with three different numbers or letters. They must observe each of the three powders, determine which one they had based on their written data from days before and provide a justification for their choice. It is not as easy as it sounds.  

     As a teacher I pick corn starch, plaster of paris and flour. Some students get the same as others and some get different powders. Sometimes they combine powders, add too much water, write down a procedure that is impossible to follow, forget to write down the large black number I placed on the side of the cup to identify the powder, record only qualitative information, lose their data and write in a way that is impossible to read. That is O.K. I would rather have them do it on the first lab and learn an important lesson and then do better on the next lab (which is what usually happens). Do you have a quick activity or experiment that helps get kids thinking and doing and gets them out of the summer mode?  Please share...would love to hear from you....