This exercise reviews forms of energy—light, sound, heat, and electricity—along with related concepts. Students learn that light and heat can travel through space, but sound cannot because it needs a medium. They explore echoes, rainbows, and the transformation of electrical energy into light, sound, and heat. Practical activities include understanding heat flow, comparing torches with and without reflectors, identifying conductors for completing an electric circuit, and making a simple cup-and-string telephone to demonstrate how sound travels through vibrations.