Final answer:
Dissolved salt in water dissociates into component ions, but in the case of an eggshell, which is primarily made of calcium carbonate, there is typically no reaction with the dissolved ions. Therefore, the compound on the eggshell remains unchanged unless the added ionic species are known to react with calcium carbonate.
Step-by-step explanation:
When salt is added to a solution and dissolves, it dissociates into its component ions. The impact of salts dissolving in water varies depending on factors like their constituent ions and the interactions they have with other substances already present in the solution. If the solution contains elements like eggshell, which is primarily composed of calcium carbonate (CaCO3), the dissolved ions from the salt do not typically react with it in a simple dissolution process.
Given that salt (NaCl) dissociates into Na+ and Cl− ions in water and these ions are from strong acids and bases, they are unlikely to hydrolyze or react with water to change its acidity or basicity significantly. Regarding the compound on the eggshell, unless the specific ionic species added have a known reactivity with calcium carbonate (such as an acid stronger than the carbonate's acidic strength, which would dissolve the eggshell), the compound on the eggshell remains unchanged, which corresponds to Option 1.