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Benign: present in some organisms, sometimes bioaccumulating, but generally having no apparent effects (except possible harmful effects, notes "a" or "b"). 1: Extremely rare on the Earth's surface (less than 1×10 −7 %, i.e. less than 1/10 as common as the least common essential element, selenium), thus has low potential for any kind of ...
Nevertheless, the effects of low doses are mostly unknown so many regulations exist to avoid unnecessary risks, such as skin or internal exposure. Due to the low penetration power and many variables involved it is hard to convert a radioactive concentration to a dose. 1 μCi of P-32 on a square centimetre of skin (through a dead layer of a ...
The Rare Earth hypothesis argues that planets with complex life, like Earth, are exceptionally rare.. In planetary astronomy and astrobiology, the Rare Earth hypothesis argues that the origin of life and the evolution of biological complexity, such as sexually reproducing, multicellular organisms on Earth, and subsequently human intelligence, required an improbable combination of astrophysical ...
Radiolysis is the dissociation of molecules by ionizing radiation.It is the cleavage of one or several chemical bonds resulting from exposure to high-energy flux.The radiation in this context is associated with ionizing radiation; radiolysis is therefore distinguished from, for example, photolysis of the Cl 2 molecule into two Cl-radicals, where (ultraviolet or visible spectrum) light is used.
US Geological Survey researchers say there could be 5.6 trillion metric tonnes of hydrogen in rocks and underground reservoirs Small fraction of hydrogen trapped under Earth can power humanity for ...
Radiation damage is the effect of ionizing radiation on physical objects including non-living structural materials. It can be either detrimental or beneficial for materials. Radiobiology is the study of the action of ionizing radiation on living things, including the health effects of radiation in humans.
Today's tritium cannot be from BBN, due to tritium's short half-life, 12.3 years. Today's 3 H concentration is instead governed by nuclear reactions and cosmic rays. The beta decay of 3 H to 3 He releases an electron and an antineutrino, and about 18 keV of energy. This is a low-energy decay, so the radiation cannot permeate skin.
The Winchcombe meteorite is a rare find, with a similar hydrogen isotope ratio to the water on Earth. Recovering a meteorite within 12 hours of arrival means it is as pristine a specimen as we can ...