First you have to clarify whether this is a commercial product or if it was synthesized by you or a collaborating lab. If the former is true, you have to read the data sheet that came with the product or follow the related articles in the product's website. (e.g. density =5.4 g/mL at 25 °C for the nanopowder you mention supplies by Sigma Aldrich.) Some of the other physical properties you mention strongly depend on the synthesis route and parameters used during fabrication. If you have taken the nanoparticles from another lab try following their articles otherwise you have to onduct your own characterization