2. Observe Why would it
be difficult to sift the iron
filings from the sand?

It is difficult to sieve the iron

filings from the sand because iron filling and sand particles are of the same size. So this method of removal of iron fillings from the sand is not useful. For removing iron fillings from the sand particles, we use magnetic force for it. When a magnet is placed near the sand having iron filling, they attract the iron filling toward itself. So for this, magnets are the best.

micro/nanoscale topography surface exhibits many prominent properties and is extensively employed in biomedical device, microfluidic device and energy device fabrication. additionally, the clinical applications of biomaterials can be largely expanded with of nanostructured surfaces.