Answer:
In Step 1 of the flowchart, the students separate the large broken shells from the mixture of sand, small nails, and white crystals by picking them out by hand. This leaves them with a mixture of sand and white crystals.
In Step 2, to separate the small nails from the mixture, the students can use a magnet. Magnetic materials like nails can be attracted to a magnet, allowing the students to easily remove them from the mixture. This will leave them with a mixture of sand and white crystals.
In Step 3, to separate the sand from the white crystals, the students can dissolve the mixture in water. The sand will sink to the bottom, while the white crystals will stay suspended or float in the water. The students can then carefully pour off the water, leaving behind the white crystals.
This stepwise process of separation allows the students to isolate the white crystals from the original mixture in the bucket.