Metal Cluster, Tetrahedral, 4 Prong, Bag of 100

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1. Great for grain boundary networks

   Posted by Trevor on 20th Feb 2015

   In soap bubbles and polycrystals, the grain edges must meet at the tetrahedral angle, which these clusters enforce perfectly. Very good physical models of grains can be built using flexible tubing, which establishes force balance and shows the residual curvature in the edges and faces. The product is useful for constructing all kinds of physical models, higly recommended!

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2. Great for office hours

   Posted by Michelle Francl on 15th Nov 2014

   I buy these in bulk, along with other centers and the tubing. Cut the tubing into thirds and then I have small models I can use with students in office hours, inexpensive enough to let them take them away. When we start VSEPR theory I give everyone a tetrahedral center, a TBP and an octahedral center, along with 4 pieces of tubing of various color (to cut up into 12 "atoms" they can use) and while I lecture on the material, everyone is asked to build their own models.

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