Similarly, in gases that have been ionized by radioactivity, by the ultraviolet rays of sunlight, by electromagnetic waves, or by a strong electric field, a two-way drift of ions takes place to produce an electric current through the gas.
(gases; have been ionized; by radioactivity) (a two-way drift of ions; takes; place; L:in gases)
gases a two-way drift of ions
have been ionized takes
by radioactivity
place L:in gases