Which of the following is an example that includes evidence of a chemical reaction?

A. A tomato is placed into a blender and chopped up into smaller pieces.

B. A solid block of ice is heated and it completely melts into a liquid.

C. Sugar that is burned gives off an odor and turns brown and then black.

D. A sample of zinc is placed in water and it settles to the bottom

1 answer

The answer is C. Sugar that is burned gives off an odor and turns brown and then black. This is an example of a chemical reaction because the burning of sugar involves a chemical change where the sugar molecules are broken down into simpler molecules, which produces a change in color and odor. The other options don't involve a chemical reaction but rather a physical change - chopping up of tomato, melting of ice, and settling of zinc in water.