Ionization

[Rennhack]

The process of adding one or more electrons to, or removing one or more electrons from, atoms or molecules, thereby creating ions. High temperatures, electrical discharges, or nuclear radiation can cause ionization.

[Rennhack]

http://www.epa.gov/radiation/understand/radiation.htm
http://www.epa.gov/radiation/understand/ionize_nonionize.htm