Estimate the thickness of polymer coating (composed of C,O and H only) on nonporous spherical silica particles if the specific surface area of these particles is 120m2/g, and the weight loss of the coated sample (measured by thermogravimetry in air) caused by the decomposition of this polymer is 27%. Density of silica and polymer are 2.2g/cm3 and 1.5g/cm3, respectively