In this demo, a polyethylene strip is charged by rubbing with wool. The strip is then used to test what happens to the flow of charge when the strip is placed in contact with a conductor (iron nail) and the materials are then moved towards a neutral object. An extension to the demo enables students to test what happens when an insulator (eraser) is used in place of the conductor (iron nail).
In this activity, students mix a given quantity of salt with a fixed volume of water. Mass and volume measurements are made before and after mixing to determine if these quantities change. Students... read more
Cells require a constant supply of glucose and oxygen to produce energy. Cellular respiration occurs in the mitochondria of a cell. As a result of this process, large quantities of waste carbon... read more