Is it possible to have a chemical change without a physical change?

Chemical or physical change?

• is toothpaste that you left in the sink that dried out and stuck like glue a physical or chem change? also wat about leaves changing colors in the fall? is it physical because changing color is usually physical change. scrambling an egg s physical or chemical change?

• Answer:

  The dried toothpaste in the sink is neither a physical or chemical change. It is a change in formulation, also known as composition. Dried toothpaste is dehydrated and, therefore, it's physical characteristics have changed. Theoretically, it should return to normal once it is re-hydrated. Leaves changing color is more of a chemical change. The photosynthetic producing chlorophyll no longer dominates the leaf and so other chemicals (Carotenoids, Anthocyanins, etc) take over. Again, this is more of a change in composition, however, since there is less chlorophyll, the chemistry of the leaf is also altered. Your last example is truly a physical change. Scrabling an egg in a blender is a physical change. However, making scrambled eggs is a chemical one... Hope this helps!!!