PBS
Pbs Learning Media: String Theory: Elementary Particles
This interactive activity from the NOVA Web site looks at the fundamental forces and particles that make up all matter. A thorough description of each elementary particle is provided including their mass, charge, spin, strength, and range.
CK-12 Foundation
Ck 12: Physical Science: Fundamental Particles
[Free Registration/Login may be required to access all resource tools.] Investigates fundamental particles and their discovery, and how they relate to fundamental forces.
Encyclopedia Britannica
Encyclopedia Britannica: Nobel Prizes: Carl David Anderson
This site from Encyclopedia Britannica contains a brief biography of Carl Anderson (1905-1991 CE), the discoverer of the positron.