For example, the brown crust on atoaste d marshmallow is the result of sugar changing to iffer-ent substances in a mixture called caramel. A change in matterthat produces one or more new substances is a chemicalchange, or chemical reaction. The burning of gasoline in acarâs engine is a chemical change.
How much brain power does the average person use? About only 10% Though an alluring idea, the 10 percent myth is so wrong it is almost laughable, says neurologist Barry Gordon at Johns Hopkins School of Medicine in Baltimorâ¦e.
The biggest part of the brain is the cerebrum. The cerebrum makes  up 85% of the brain's weight, and it's easy to see why. The  cerebrum is the thinking part of the brain an â¦ d it controls your  voluntary muscles-the ones that move when you want them to.cientists do know for sure that the right half of the  cerebrum controls the left side of your body, and the left half  controls the right side   The cerebellum is the second largest part of the brain. It controls  muscle coordination, maintains normal muscle tone and posture, and  coordinates balance.