Salt versus Sugar

In science we have done a lot of things that scientists do.  We have observed, asked questions, made hypothesis, developed a method and performed experiments.  We have recorded data and check our results to see if our hypothesis was correct.

One experiment compared salt and sugar.  We noticed what happened when we tried to melt water with salt and sugar, and what happened when we tried to freeze water with salt and sugar.  Our freezing experiment began with three cups of ice.  We added a tablespoon of salt to one cup, a tablespoon of sugar to the second cup, and left the third cup with just ice.  We observed and recorded our observations over time.  As we began the experiment, one student asked "Why do they put salt down on the roads in the winter?"  We answered that question as we observed!

                                          [left to right- salted ice, sugared ice, plain ice]

As you can see, the salted ice melted the quickest.  It began to melt right away, putting holes into the ice cubes.  The sugared ice melted second.  The plain ice took the longest to melt.

This experiment helped us to predict what would happen when salt water and sugar water was frozen.  The salt water took the longest to freeze!  Scientists use their schema (past experience and knowledge they already have) to make predictions for new experiments.  We did that too!