Chemistry help me
A student mixes 20.0g of white KCI crystals with distilled water in a beaker. After the mixture was stirred, no crystals are visible and the solution is clear. After several days, all of the water evaporates and white crystals are found in the beaker. Which of following pieces of experimental evidence would best help the student to confirm that a new compound had not been made and that only a physical change occurred?
A. The solution does not change color after stirring
B The KCI crystals are no longer visible after mixing with water
C there is a temperature change in the solution during the dissolving process.
D after the water had evaporated the white crystals in the beaker have a mass of 20g.