Write a 500-750 word description of an item or a piece of equipment used in your field (for example, a GPS device, bluetooth technology, etc). In a note preceding the description, specify your audience and indicate the description (general or particular) you are writing. If you use sources, be sure to cite them correctly.

In a unit cell of fcc structure, indicate the position of one of the tetrahedral interstitial sites by plotting the corresponding tetrahedron. do the same for one of the octahedral interstitial sites (in a separate fcc unit cell). mark the positions of all the tetrahedral and octahedral interstitial sites in the unit cells. how many equivalent tetrahedral sites and how many equivalent octahedral sites are contained in a fcc unit cell, respectively. what is the coordination number for a tetrahedral site and what is the coordination number for an octahedral site?