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Science Misconception: Do Objects Disappear When The Dissolve?
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Science Area:  Chemistry 

Misconception:

 

When things dissolve they disappear.

 

Facts:

When a solid such as sugar or salt is mixed together with water the solid appears to disappear.  The solid does not truly “disappear”.  When water and a solid such as salt are mixed together all of the pieces of the solid are separated and break apart from each other by the water.  The salt atoms then blend with the water molecules to form a solution.  Water is known as the Universal Solvent because it dissolves more substances than any other solvent.   The solid that is dissolved by the water is known as the solute. 

 

 

Explanation: 

 

Although we can no longer see solids once they have been dissolved in water they are still present.  Children may think they have disappeared because they are no longer visible.  When salt is dissolved in water, the salt atoms then blend with the water molecules to form a solution.  The salt is still present, but has been broken down by the water molecules. 

 

Suggested Activity:

 

Boil plain water and salt water.  Once the water has evaporated, the salt will be left in the pan and visible proving it did not disappear. 

Source:  Retrieved on 6/17/07   http://arn.org/realscience/chempre1sample/chempre6%20.pdf