This site from Cornell University provides a very short, very telling comparison of matter and charge. This is a good site to check out on the subject, with a chart diagram to help with further information.

Here is a 1-5 day unit on electromagnetic radiation that features a teacher guide and student activities with extensions.

Defines sound, how it travels, the components of a sound wave, the different types, and other fun facts.

Labeled diagram showing the main components of a wave.