This is a great little device to use when describing open and closed circuits. This 1.5 inch ball contains two small metal electrodes. When electrodes are touched simultaneously, the Energy Ball makes a buzzing and sound flashes.

A great group activity is to have students in the class hold hands in a large circle. The teacher joins the circle and has the student beside him/her touch one of the electrodes while the teacher touches the other electrode. The whole class provides the circuit that when closed, lights the ball and creates the buzzing sound. When a hand is dropped the circuit becomes open and the light is gone along with the sound. The class must work together and the light of success reaches all.