Wikimedia
Wikipedia: Atomic Number
Wikipedia provides the definition of the term, "Atomic number," a term used in chemistry and physics to represent the number of protons in the nucleus of an atom.
Other
Science Playwiths: Electricity and Magnet Playwiths
A relatively easy set of instructions for building a Leyden jar, and an easy-to-understand explanation of how it works.
Other
Museum of Science: Simple Electroscope
Resource explains how to build and use a simple electroscope.