What is the last step in the crystal-making process?

• A. Filter, dry and collect the crystals.
• B. Heat again to crystallisation.
• C. Stir the solution.
• D. Allow to warm to room temperature.

Answer: (A)

When crystals are ready, the final step is to separate and prepare them for use. Filtering removes the remaining liquid, leaving the solid crystals on the paper. Drying is important so the crystals aren’t left wet, which could dissolve or alter them, and to make them easy to weigh or observe. Collecting brings the dry crystals together for storage or further analysis. This order—separating from the solution, drying, and then gathering the crystals—is what yields a clean sample of solid crystals. Stirring helps form crystals, and warming or reheating can drive crystallisation earlier in the process, but they aren’t the final step.