Tonya plugged in a toaster. She placed two slices of bread in the toaster, pushed down the lever, and the heating coils glowed. She noticed that only one form of energy toasted the bread. What form of energy was wasted in the process?

The questions have been asked in several important state and regional science exams in the United States. For example: TAKS-Texas Assessment of Knowledge and Skills, New York State Educational Department Regents exams, California Standards Test, etc.