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 (Latin America) no news since of any further seasons. Mexico is also the runner-up in this season.<br> As of the sixth season, the Latin American version of The Amazing Race has visited 15 countries and has visited only the Americas (except Canada and the United States). The Amazing Race (Latin America) The Amazing Race, formerly known as The Amazing Race en Discovery Channel (), is a reality game show based on the American series of the same name, "The Amazing Race". On 15 October 2008, a Latin American version of the show was announced by Discovery Channel Latin America in association with