Question

which physical method can be used for obtaining a sample of salt from a small beaker of salt water?
boiling
freezing
chromatography
sorting

Explanation:

Boiling the salt - water will evaporate the water, leaving the salt behind. Freezing separates components based on different freezing points, not suitable here. Chromatography is for separating mixtures based on differential affinities to a stationary phase and is not for salt - water separation. Sorting is for separating solid - solid mixtures by physical properties like size, color etc., not for salt - water.

Answer:

boiling