Roentgen (unit) Roentgen (unit) The roentgen or röntgen () (symbol R) is a legacy unit of measurement for the exposure of X-rays and gamma rays. It is defined as the electric charge freed by such radiation in a specified volume of air divided by the mass of that air. In 1928 it was the first international measurement quantity for ionising radiation to be defined for radiation protection, and was an easily replicated method of measuring air ionization directly by using an ion chamber. It is named after the German physicist Wilhelm Röntgen, who discovered X-rays. Although relatively easy to measure, it had
The Amazing Race en Discovery Channel 2 The Amazing Race en Discovery Channel 2 The Amazing Race en Discovery Channel is a Latin American version of the American reality television show "The Amazing Race". The second season featured eleven teams of two, with a pre-existing relationship, in a race across Latin America to win US$250,000. The second season premiered on Sunday 26 September 2010 at 11.00 p.m (). This was the final season to be aired in Discovery Channel Latin America. Mexican brothers Mauricio and Carlos Coarasa are the winners of the race. Discovery Channel greenlit the second installment on November 2009. Race locations were scouted in