6. AgBr possesses the rocksalt crystal structure and is an important component in photographic film (you know, the stuff we used before digital cameras and cell phones). Its use in such applications is due to its very low room temperature (25°C) cation Frenkel defect formation energy of 1.16 eV, which gives AgBr a unique and high sensitivity to light exposure. Givern this, answer the following questions. (a) Write the Kroger-Vink defect notation (not the full reaction equation) for the cation Frenkel defect in AgBr. (b) On what type of interstitial site will these cations reside, and why? (c) Calculate the density (#/cm) of cation interstitials in AgBr at room temperature. The density of AgBr is 6.473 g/cm3. Note that the Arrhenius formula for a Frenkel defect is slightly different than for a regular vacancy, since there are two parts (vacancy and interstitial): NF=Noexp(-EA/2k7)