Step-by-step explanation:
Generally, materials are separated according to differences in their physical properties. During the separation process, it is important not to chemically change any of the parts of the mixture if possible. This avoids costly chemical processes and loss of material. It is best to try to separate one component at a time, which means that this experiment can be expected to have at least three stages, corresponding to the removal of each component from the mixture.
Physical properties
In this experiment, the three constituent materials in the mixture are solids with significantly different physical properties, which makes separation easier.
Iron is a magnetic solid which is insoluble in water.
Salt is a non-magnetic solid which is soluble in water.
Sand is a non-magnetic solid which is insoluble in water.
IN SPECIFIC:
Iron is magnetic and the other two not, which means a magnet could be used to attract the iron filings out of the mixture, leaving the salt and sand. Salt is water soluble, while sand is not. This means the two can be mixed in water and stirred. The salt will dissolve and the sand willnot.