Why does salt melt ice?
Salt lowers the freezing point of water, if you add salt to
water, it will be harder to turn it into ice. For example, you need
to make metal very hot to melt it, however you don't need as much
to melt ice. you don't need as much heat to melt salted ice as you
do to melt ice. So salted ice melts faster.
Salt will melt Ice
Salt will dissolve in water
Salt melts ice into water by contact, as it melts the ice, it dissolves, as it dissolves into the water it changes the chemical composition of the water decreasing the temperature at which it will freeze. Technically this is changing the thermal conductivity of water... The more salt in water, the colder the water needs to be before it can freeze. This concentration of Salt in water is referred to as salinity.