Introduce the concept of electricity to your fourth-graders. Demonstrate the significance of electricity by turning off all the electrical items in the room, such as the lights, computers and monitors. Ask them to think about what life was like before electricity was discovered. Instruct your fourth-graders to write a diary entry describing a typical day without electricity to help them think about how difficult it would be to achieve everyday tasks without it.
Gather your youngsters around the science classroom's main bench or table and lay out a tablespoon of fine black pepper. Ask a volunteer to help you and hand him a plastic comb and a wool cloth. Have your volunteer rub the plastic comb with the wool cloth for 30 seconds --- it only needs about five seconds of rubbing to be effective, but you can use the time to explain how the comb is becoming positively charged while the pepper is negatively charged. Get your volunteer to pass the comb to within two inches of the surface of the pepper --- the pepper is attracted to the comb. Explain to the fourth-graders that this occurs because the pepper is negatively charged and attracted to the positively charged comb.
Lead your fourth-grade class through this research project to investigate the different stages of electrical power production. Split your class into five equal groups and provide each a large sheet of paper, pens, stickers, tape, safety scissors, glitter glue and other decorative materials. Ask each group to design a poster for one of the five phases of electric production: coal mining; coal at the generation center; high-voltage electric current running from transmission line to transformer drum; lower voltage current traveling to homes; and electric appliances being used at home. Help each group with its poster, making sure the students are well-acquainted with the phase of electric power production they are working on. Pin the completed posters on a board in order and talk the class through each stage to conclude the project.
Maintain a theme of health and safety throughout your electricity lessons. You do not need to address it as a separate project; remind students about the safe way to use appliances at home, for example, while you teach them the basics of science laboratory electrical safety. Or teach students about how they should only ever handle a live electric circuit with one hand at a time, thereby limiting the possibility of a charge passing through their chest.