Procedure for the experiment.
1. crush 1 stick of classroom chalk (a mixture of limestone and gypsum) finely.
2. mix chalk into 50 ml of water in a beaker.
3. pour the mixture through filter paper into another beaker. the water appears to be "pure."
4. boil the water or let it evaporate away.
what is left?

A solid residue of limestone and some gypsum.

Explanation:

In step 2, some of the limestone and gypsum in the chalk dissolve in the water. When the mixture is filtered, the dissolved substances remain in the water. When the water is boiled off or evaporated, the solid substances remain behind.

the answer is na (sodium)

2b2t

explanation:

2b2t