Reflection: Routines and Procedures Density Part II and Review - Section 3: Elaborate


At this point in the year I begin to switch students into different lab groups than simply who they are sitting with at their tables.  This is a practice which I continue to use for most labs throughout the school year. 

I have students move to lab groups randomly through using cards. 

  • I use a deck of cards with the Aces through 8's for groups 1-8. 
  • I randomly give one card to each student (unless I specifically want some students to not work together and will make sure they have different cards as I walk around)
  • I then have students go up to their lab stations. 
  • If a class has more than 32 students than I will just tell the last few students to pick a station to make a group of 5, and in classes with less than 32 students I will make sure that all groups have at least 3 before any group has 4 students while passing out cards. 

I find that students work more efficiently when they are placed in cooperative groups with specific roles. 

  • The attached image has an example of how I might give students roles of Primary Investigator, Post-Doc, Graduate Students, and Undergraduate Student.  I like to use the "real-world" lab roles to get them into the idea of who works in labs.
  • To help students with their specific roles I will have each suit be one of the roles.  I will simply say something like all the hearts are the Primary Investigator, etc.
  • If a group has 3 students I will combine the Primary Investigator with the Post Doc or if a group has 5 students that I will make two graduate students.
  • I will have students switch roles as they are doing the lab (for this lab I have them switch after each trial).
  • This class video demonstrates how I assign students roles and help them get situated for a lab.

  Routines and Procedures: Cooperative lab groups
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Density Part II and Review

Unit 1: Unit 1: Working as a chemist
Lesson 9 of 9

Objective: Students will be able to predict the identity of an unknown metal through performing a density lab.

Big Idea: Density is an intensive property which is useful for identifying unknown substances.

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Science, Chemistry, Scientific Method (Science Skills), dimensional analysis, culture
  100 minutes
metal density 1
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