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Specific activity (symbol a) is the ... Example: specific activity of Ra-226. For example, specific radioactivity of radium-226 with a half-life of 1600 years is ...
Radium-226 (226 Ra) is the longest-lived isotope of radium, with a half-life of 1600 years. It is an intermediate product in the decay chain of uranium-238; as such ...
Because of its relative longevity, 226 Ra is the most common isotope of the element, making up about one part per trillion of the Earth's crust; essentially all natural radium is 226 Ra. [29] Thus, radium is found in tiny quantities in the uranium ore uraninite and various other uranium minerals, and in even tinier quantities in thorium minerals.
As a result, phosphogypsum which exceeds this limit is stored in large stacks since extracting such low concentrations of radium is either not possible or not economical with current technology for either the use of the gypsum or the radium [citation needed]. Given the traditional definition of the Curie via the specific activity of 226
It was originally defined as "the quantity or mass of radium emanation in equilibrium with one gram of radium (element)", [1] but is currently defined as 1 Ci = 3.7 × 10 10 decays per second [4] after more accurate measurements of the activity of 226 Ra (which has a specific activity of 3.66 × 10 10 Bq/g [5]).
Radon is produced commercially by a solution of radium-226 (half-life of 1,600 years). Radium-226 decays by alpha-particle emission, producing radon that collects over samples of radium-226 at a rate of about 1 mm 3 /day per gram of radium; equilibrium is quickly achieved and radon is produced in a steady flow, with an activity equal to that of ...
Radium (88 Ra) has no stable or nearly stable isotopes, and thus a standard atomic weight cannot be given. The longest lived, and most common, isotope of radium is 226 Ra with a half-life of 1600 years. 226 Ra occurs in the decay chain of 238 U (often referred to as the radium series). Radium has 34 known isotopes from 201 Ra to 234 Ra.
Many years ago radium-226 and radon-222 were used as gamma-ray sources for industrial radiography: for instance, a radon-222 source was used to examine the mechanisms inside an unexploded V-1 flying bomb, while some of the early Bathyspheres could be examined using radium-226 to check for cracks. Because both radium and radon are very ...