Rontgen, Wilhelm

Rontgen s critical discovery was made in 1895 when he happened to observe that, as a cathode-ray tube was being operated in a darkened room, paper covered with barium platinocyanide lying some distance from the tube lit up with brilliant fluorescence. The fluorescence of barium platinocyanide was used at that time to establish the presence of invisible rays of the solar spectrum (such as ultraviolet). However, on this occasion, the tube had been surrounded by a close-fitting shield of black cardboard, quite opaque to ultraviolet light or sunlight. 

When Rontgen first published his results, the macabre revelation of living bone structures created a sensation, and within a month articles on the value of X rays within medicine appeared in major medical journals, x rays have been an invaluable tool in medicine, dentistry, and industry ever since. A roentgen, abbreviated as R, is the international unit of quantity or dose for both X rays and gamma rays. It is equal to the amount of x or gamma radiation that produces as a result of ionization one electrostatic tmit of charge in one cubic centimeter (0.034 ounces) of dry air. 

Ionization dissociation of a molecule into ions carrying + or - charges 

---

It was another four years before Becquerel s radiation became tmder-stood as the production of /3-rays (high energy electrons), but by then there was no question that Becquerel had discovered the instability of some atomic nuclei, and that he was richly deserving of the 1903 Nobel Prize that he shared with Pierre and Marie Curie, see also Curie, Marie Sklodowska Rontgen, Wilhelm. 

For nearly three centuries, a new element has been discovered every two-and-one-half years, on average. Undoubtedly, more will be found. Although their names and their discoveries will fikely involve controversies, their place at the table is already set. see also Alchemy Avogadro, Amedeo Bec-QUEREL, Antoine-Henri Bohr, Niels Cannizzaro, Stanislao Dalton, John Lavoisier, TVntoine Mendeleev, Dimitri Meyer, Lothar Pauli, Wolfgang Ramsay, William Rontgen, Wilhelm Rutherford, Ernest Seaborg, Glenn Theodore Thomson, Joseph John. 

---