from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Spontaneous emission of radiation, either directly from unstable atomic nuclei or as a consequence of a nuclear reaction.
- n. The radiation, including alpha particles, nucleons, electrons, and gamma rays, emitted by a radioactive substance.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Spontaneous emission of ionizing radiation as a consequence of a nuclear reaction, or directly from the breakdown of an unstable nucleus.
- n. The radiation so emitted; including gamma rays, alpha particles, neutrons, electrons, positrons, etc.
from the GNU version of the Collaborative International Dictionary of English
- n. a form of instability which is a property of the atomic nuclei of certain isotopes, which causes a spontaneous change in the structure of the nucleus, accompanied by emission of energetic radiation. The radiation emitted is usually sufficient to cause ionization in matter through which it passes, and is therefore called ionizing radiation. The radiation emitted by most radioactive substances is one of three types: alpha rays, beta rays, or gamma rays. Some chemical elements have no stable isotopes, and these are referred to as radioactive elements, and the element itself is said to possess radioactivity.
from The Century Dictionary and Cyclopedia
- n. The property possessed by certain substances of spontaneously emitting obscure rays of a nature distinct from the ether-waves of ordinary radiation.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay
Especially appealing are the ones inspired by Madame Curie, two-time Nobel prize winner who discovered radium and polonium and coined the term "radioactivity."
She may have had to exist in a state of denial to accomplish what she did: she opened up the field of radiation, coining the word radioactivity; she not only found two new elements, she found a new way to find them, using the tools of physics.
Since Marie Curie coined the word "radioactivity" in 1898, we've struggled with nuclear-weapons proliferation, we've debated the role of radiation in medical treatment, and we've considered nuclear energy as an alternative energy source to counter climate change.
During her years of work, Curie coined the term radioactivity, and named Polonium.
Although she understands nothing of radium research the journalist has an interest or a "preference" for it, because, as she puts it, radioactivity is a science where every month, there is a new discovery one reads about in the newspaper.
She had already gained experience not only in radioactivity but also in industrial chemistry and textile technology as well.
For each discipline, radium carried a different identity as it did for the various institutes involved in radioactivity research.
As Rutherford and Soddy argued, radioactivity is at once an atomic phenomenon and accompanied by chemical changes in which new types of matter are produced.
It also encourages a monolithic understanding of disciplinary practices and laboratory cultures by assuming that work in radioactivity involved tedious tasks that women performed more willingly than their male colleagues throughout the different institutional settings.
Indeed a few months later the Neues Wiener Journal published an article on American efforts to light the streets of the cities and highways using radium. 100 The anonymous journalist further argues that radioactivity is "a science that was established by a woman and thus it is romantic .... romantic for the amateur."