Salt, Water, and Ice
Some scientists may like salt as a seasoning in their food. But a lot of them like it for the interesting things it does.
For example, salt affects how water freezes. Do this experiment to discover whether it makes freezing easier or more difficult.
Fill two identical containers halfway with warm water. One-pound coffee cans or plastic food containers work well. (Never use glass containers because they may break.)
To one of the containers, slowly add table salt while stirring. The salt will seem to disappear as it dissolves. Keep adding salt until no more dissolves. You may have to use as much as one-third cup of salt.
Put both containers into the freezer and check them every two or three hours. What do you find?
Any difference between the cans must be caused by the salt because you have kept all other things the same. The containers are the same. They both have the same amount of water. Both were kept at the same temperature for the same length of time.
After doing the experiment as a scientist would, you can say, “When you add salt to water, this is what happens!”
by Ruth J. Flanigan
Source: highlightskids.com
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