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 1 In the leg's second Detour was "Mariachis" or "" . In "Mariachis", teams had to find an image of Santa Muerte under a hat worn by one of the mariachis playing. In "Trajineras", teams had to find a "trajinera" (typical boats of Xochimilco) called "Zita" and find the clue inside the boat. The Amazing Race en Discovery Channel 1 The Amazing Race en Discovery Channel (; ) is a Latin American reality television game show based on the American series, "The Amazing Race". The first season of the show featured eleven teams of two with a pre-existing relationship, in a