Answer:
When salt is poured on a slug, it causes the slug to die due to a process called osmosis. Osmosis is the movement of water molecules across a semi-permeable membrane from an area of low solute concentration to an area of high solute concentration.
In this case, the salt acts as a solute and when it comes in contact with the slug's moist skin, it creates a hypertonic solution. A hypertonic solution has a higher concentration of solute compared to the slug's body fluids. This means that the concentration of water molecules outside the slug's body is lower than inside.
As a result, water molecules from the slug's body fluids start moving out through its skin to balance the concentration of the hypertonic solution. This movement of water molecules out of the slug causes dehydration, which is harmful to the slug's cells and vital organ functions.
Furthermore, the high concentration of salt in the hypertonic solution can also damage the slug's cells by disrupting the balance of ions and interfering with various cellular processes.
In summary, pouring salt on a slug creates a hypertonic environment that leads to the movement of water molecules out of the slug's body, causing dehydration and cell damage, ultimately resulting in the slug's death.