The following sample lesson was chosen primarily because most elementary teachers are fearful of having to teach a hands-on science involving Energy and Physical Science. This exploration is more meaningful to the students if done from beginning to end. If that is not possible, stop after observing the white bread. Collect the bread slices and refrigerate. By comparing the initial state of an object to its final state, we can define changes.
Heat is a form of energy.
Let the students know ahead of time that white bread is not as good for them as whole grain bread. We are using it for experimental purposes. It is easier to see color changes. Also, we will be handling the slice a lot which would make it unsanitary. World of Energy on the chalkboard or show the transparency.