Final answer:
Throwing salt on a slug interferes with osmosis, dehydrating the slug and causing its death.
Step-by-step explanation:
Throwing salt on a slug is bad for the slug because it interferes with osmosis, which is the process by which water is transferred in and out of cells. Slugs have a high concentration of water inside their cells, while salt has a low concentration. When salt is sprinkled on a slug, it causes the water to move out of the slug's cells, dehydrating it and eventually leading to its death.
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