Other ways to separate out poppy seeds sand salt and iron filings?

Answer 1

Think of the physical properties of the things you are separating... Iron filings are ferromagnetic---they can be attracted by a magnet. Salt, poppy seeds, and sand are not. Salt is soluble in water---if placed in water the salt crystals will break up into soluble Na+ and Cl- ions. Not sure where to go with sand and poppy seeds except to suggest that a poppy seed is probably 4-5 times bigger than a grain of sand. Assuming that is true, you could use the following procedure: 1. Pour the mixture over a strong magnet. All the components except the iron filings should pass right over the magnet while the filings will be stuck to the magnet. 2. Dissolve the remaining mixture in water. Filter out all the solid that does not dissolve and dry it. 3. Find a mesh with holes large enough for the sand to fit through but too small for the poppy seeds to fit through. Run the mixture through the mesh.