briefly explain how spreading salt on ice that is at a temperature below0C (32F) can cause the ice to melt

Sure, here's a step-by-step explanation:

1. Salt lowers the freezing point of water: When salt is spread on ice, it starts to dissolve in the film of liquid water that is always present on the surface, creating a solution of water and salt.

2. This process is called "freezing point depression": The salt-water solution freezes at a lower temperature than pure water. This means that ice, which is frozen water, will start to melt even if the temperature is below the normal freezing point of water (0°C or 32°F).

3. The ice starts to melt: As the salt continues to dissolve and the concentration of the solution increases, even more ice can melt, because the freezing point continues to decrease.

4. The process continues: The more salt you add, the more the freezing point is lowered (up to a point), so even on a very cold day, salt can help to melt ice.

5. The end result: Eventually, the ice turns into liquid water, even though the temperature is below freezing. This is why salt is often used to de-ice roads and sidewalks in winter.