electricity vs radioactivity

electricity

noun
  • Originally, a property of amber and certain other nonconducting substances to attract lightweight material when rubbed, or the cause of this property; now understood to be a phenomenon caused by the distribution and movement of charged subatomic particles and their interaction with the electromagnetic field. 

  • Electric power/energy as used in homes etc., supplied by power stations or generators. 

  • The study of electrical phenomena; the branch of science dealing with such phenomena. 

  • A feeling of excitement; a thrill. 

radioactivity

noun
  • The radiation so emitted; including gamma rays, alpha particles, neutrons, electrons, positrons, etc. 

  • Spontaneous emission of ionizing radiation as a consequence of a nuclear reaction, or directly from the breakdown of an unstable nucleus. 

How often have the words electricity and radioactivity occurred in a corpus of books? (source: Google Ngram Viewer )