Electricity and magnetism are related effects that have many useful applications in everyday life.

We tend to identify electricity and magnetism with the ways we experience them in our daily lives. From that perspective, electricity primarily consists of the current that flows in wires in our homes and that provides us with light, heat, refrigeration, motor-driven devices, and the modern electronics of communication/ entertainment/ information. We also experience electricity as being stored in batteries, and as somehow also connected with our occasional static electricity shocks and lightning displays.

We have less daily experience with magnetism. Most of us relate to magnetism primarily as the mysterious force that enables us to place a variety of objects on our refrigerator doors. We consider it to be connected exclusively with metals, and to have little or no relation to electricity.

Actually, electricity and magnetism are very intimately related. They are both part of the same fundamental physical force, known appropriately enough as the electromagnetic force. To place that force in perspective, physicists consider that there are four fundamental forces that govern the interactions of matter in our universe. Two of these forces work at the level of the atomic nucleus. These two nuclear forces relate to how protons and neutrons stick together, and how some atoms are radioactive and decay. Another force is gravity, explaining how all matter attracts each other. The electromagnetic force accounts for everything else, such as essentially all of chemistry and biology. The electromagnetic force accounts for how elements and molecules interact with each other, how plants capture energy from the sun, and how all of life uses matter and energy to grow, reproduce, and change.

The electromagnetic force is much stronger than gravity. Think about rubbing a balloon and then using the tiny amount of excess electrical charge produced on the surface of the balloon to pick up small pieces of paper. The entire mass of planet Earth is pulling on those pieces of paper using gravity to hold them on the table. The electromagnetic force exerted by the balloon overcomes the gravity of the entire planet.

We do not expect Grade 4 students to have this bigger conception of electromagnetism. What we want to do is to help them realize that electricity and magnetism are related to each other, and that many devices in their daily lives are based on the properties of electricity and magnetism.

Electromagnets provide the most compelling experience demonstrating that electricity and magnetism are related to each other. Through this phenomenon, we discover that electric currents produce magnetic effects (Standard 1c). Investigating the effects of electric currents on a compass can reinforce this concept.

Perhaps even more surprising, moving a magnet can make electric current flow in wires. This phenomenon should be very famous. It is the basis for how our society makes the vast majority of the electricity that powers our homes and industries. Generators in electric power stations (including those burning fossil fuels, using nuclear energy, or running on wind or water) utilize magnets that move near coils of wire to make the electric current that is then distributed around the country.

Another feature of magnetism and electricity may help students connect these two phenomena. In both cases, like repels like, and unlike attract each other. Positive electric charges repel other positive electric charges but attract negative electric charges. A north seeking magnetic pole will repel another north seeking magnetic pole but will attract a south seeking magnetic pole.

At the level of Grade 4, we do not want to try to “explain” these phenomena. The physical basis for electricity and magnetism (that is, the nature of the electromagnetic force) is far too complex for this grade level. Any analogy that you use is more likely to confuse students and introduce significant misconceptions than it is to explain the underlying phenomena. It is much better for students, and all of us, to realize that electricity and magnetism are wondrous phenomena with deep concepts underlying common observations such as a magnet sticking to a refrigerator or a light bulb illuminating a dark space.

The order in which the standards were written does not imply that they are supposed to be taught in that sequence. As in all the strands, these standards can be taught in many ways and in many sequences. The concept map below provides one way to organize these standards. The wording of some of the standards has been slightly changed for space reasons and to emphasize a particular conceptual flow.

[A different concept map for these standards is on page 42 of the book "Making Connections" available from the California Science Teachers Association (CSTA).]