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 salt - water causes the water to evaporate, leaving the salt behind. Freezing separates components based on different freezing - points, not suitable here. Chromatography is for separating mixtures based on different affinities for a stationary and mobile phase, not for salt - water separation. Sorting is for separating solid particles by physical characteristics, not applicable to salt - water.

Answer:

boiling