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- https://chem.libretexts.org/Courses/University_of_North_Texas/UNT%3A_CHEM_1410_-_General_Chemistry_for_Science_Majors_I/Text/04%3A_The_Structure_of_Atoms/4.08%3A_RadiationJust prior to the turn of the twentieth century, additional observations were made which contradicted parts of Dalton’s atomic theory. The French physicist Henri Becquerel discovered by accident that ...Just prior to the turn of the twentieth century, additional observations were made which contradicted parts of Dalton’s atomic theory. The French physicist Henri Becquerel discovered by accident that compounds of uranium and thorium emitted rays which, like rays of sunlight, could darken photographic films. Although themselves invisible to the human eye, the rays could be detected easily because they produced visible light when they struck phosphors such as impure zinc sulfide.
- https://chem.libretexts.org/Courses/Westminster_College/CHE_180_-_Inorganic_Chemistry/14%3A_Chapter_14_-_p-Block_Elements/14.4%3A_Group_16/Chemistry_of_Tellurium_(Z%3D52)Discovered by von Reichenstein in 1782, tellurium is a brittle metalloid that is relatively rare. It is named from the Latin tellus for "earth". Tellurium can be alloyed with some metals to increase t...Discovered by von Reichenstein in 1782, tellurium is a brittle metalloid that is relatively rare. It is named from the Latin tellus for "earth". Tellurium can be alloyed with some metals to increase their machinability and is a basic ingredient in the manufacture of blasting caps. Elemental tellurium is occasionally found in nature but is more often recovered from various gold ores.
- https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Supplemental_Modules_and_Websites_(Inorganic_Chemistry)/Descriptive_Chemistry/Elements_Organized_by_Block/3_d-Block_Elements/Group_03/Chemistry_of_ActiniumSamples of actinium quickly decay to thorium and francium. The longest-lived isotope (Ac-227) has a half-life of 21.8 years. The element is obtained as an impurity in pitchblende, an ore mined for its...Samples of actinium quickly decay to thorium and francium. The longest-lived isotope (Ac-227) has a half-life of 21.8 years. The element is obtained as an impurity in pitchblende, an ore mined for its uranium content. One-tenth of one gram of actinium can be recovered from 1 ton of pitchblende!
- https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Inorganic_Chemistry_(LibreTexts)/08%3A_Chemistry_of_the_Main_Group_Elements/8.11%3A_The_Oxygen_Family_(The_Chalcogens)/8.11.05%3A_Chemistry_of_Tellurium_(Z52)Discovered by von Reichenstein in 1782, tellurium is a brittle metalloid that is relatively rare. It is named from the Latin tellus for "earth". Tellurium can be alloyed with some metals to increase t...Discovered by von Reichenstein in 1782, tellurium is a brittle metalloid that is relatively rare. It is named from the Latin tellus for "earth". Tellurium can be alloyed with some metals to increase their machinability and is a basic ingredient in the manufacture of blasting caps. Elemental tellurium is occasionally found in nature but is more often recovered from various gold ores.
- https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Supplemental_Modules_and_Websites_(Inorganic_Chemistry)/Descriptive_Chemistry/Elements_Organized_by_Block/2_p-Block_Elements/Group_18%3A_The_Noble_Gases/Z086_Chemistry_of_Radon_(Z86)Radon is a colorless, odorless gas, the primary source of indoor air pollution. It sinks in air because it has a high density as is therefore often found in the basements of homes, particularly in are...Radon is a colorless, odorless gas, the primary source of indoor air pollution. It sinks in air because it has a high density as is therefore often found in the basements of homes, particularly in areas where with a lot of shale and boulders in the soil. Radon results from the radioactive decay of radium in the soil, and it further decays to produce radioactive daughters including polonium and lead.
- https://chem.libretexts.org/Bookshelves/Analytical_Chemistry/Instrumental_Analysis_(LibreTexts)/32%3A_Radiochemical_MethodsRadiochemical methods of analysis take advantage of the instability of some elemental isotopes, which decay through the release of alpha particles, beta particles, gamma rays, and/or X-rays, provide f...Radiochemical methods of analysis take advantage of the instability of some elemental isotopes, which decay through the release of alpha particles, beta particles, gamma rays, and/or X-rays, provide for a selective analysis for one analyte in a complex mixture of other species without the need for a prior separation. In this chapter we review the basics of radioactive decay and its direct application to samples, and two other methods of importance: neutron activation and isotope dilution.
- https://chem.libretexts.org/Bookshelves/Introductory_Chemistry/Introductory_Chemistry_(CK-12)/24%3A_Nuclear_Chemistry/24.02%3A_Nuclear_Decay_ProcessesThis page discusses food irradiation, a method using ionizing radiation to kill harmful bacteria while preserving nutritional value. It effectively targets parasites and pests but does not affect viru...This page discusses food irradiation, a method using ionizing radiation to kill harmful bacteria while preserving nutritional value. It effectively targets parasites and pests but does not affect viruses.
- https://chem.libretexts.org/Courses/Valley_City_State_University/Chem_122/Chapter_9%3A_Nuclear_Chemistry/9.3%3A_Patterns_of_Nuclear_StabilityProtons and neutrons are called nucleons and a nuclide is an atom with a specific number nucleons. Unstable nuclei decay spontaneously are radioactive and its emissions are called radioactivity. Nucl...Protons and neutrons are called nucleons and a nuclide is an atom with a specific number nucleons. Unstable nuclei decay spontaneously are radioactive and its emissions are called radioactivity. Nuclei are bound by the strong nuclear force. Stable nuclei generally have even numbers of protons and neutrons with a ratio of at least 1. Nuclei that contain magic numbers of protons and neutrons are often especially stable including superheavy elements, with atomic numbers near 126.
- https://chem.libretexts.org/Courses/Duke_University/CHEM_210D%3A_Modern_Applications_of_Chemistry/3%3A_Textbook-_Modern_Applications_of_Chemistry/01%3A_Primer/1.01%3A_The_Structure_of_Atoms/1.1.07%3A_RadiationJust prior to the turn of the twentieth century, additional observations were made which contradicted parts of Dalton’s atomic theory. The French physicist Henri Becquerel discovered by accident that ...Just prior to the turn of the twentieth century, additional observations were made which contradicted parts of Dalton’s atomic theory. The French physicist Henri Becquerel discovered by accident that compounds of uranium and thorium emitted rays which, like rays of sunlight, could darken photographic films. Although themselves invisible to the human eye, the rays could be detected easily because they produced visible light when they struck phosphors such as impure zinc sulfide.
- https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Supplemental_Modules_and_Websites_(Inorganic_Chemistry)/Descriptive_Chemistry/Elements_Organized_by_Block/2_p-Block_Elements/Group_16%3A_The_Oxygen_Family_(The_Chalcogens)/Z052_Chemistry_of_Tellurium_(Z52)Discovered by von Reichenstein in 1782, tellurium is a brittle metalloid that is relatively rare. It is named from the Latin tellus for "earth". Tellurium can be alloyed with some metals to increase t...Discovered by von Reichenstein in 1782, tellurium is a brittle metalloid that is relatively rare. It is named from the Latin tellus for "earth". Tellurium can be alloyed with some metals to increase their machinability and is a basic ingredient in the manufacture of blasting caps. Elemental tellurium is occasionally found in nature but is more often recovered from various gold ores.
- https://chem.libretexts.org/Bookshelves/Inorganic_Chemistry/Supplemental_Modules_and_Websites_(Inorganic_Chemistry)/Descriptive_Chemistry/Elements_Organized_by_Block/2_p-Block_Elements/Group_17%3A_The_Halogens/0Group_17%3A_Physical_Properties_of_the_Halogens/Group_17%3A_General_Properties_of_HalogensHowever, if the halogen is bonded to oxygen or to another halogen, it can adopt different states: the -2 rule for oxygen takes precedence over this rule; in the case of two different halogens bonded t...However, if the halogen is bonded to oxygen or to another halogen, it can adopt different states: the -2 rule for oxygen takes precedence over this rule; in the case of two different halogens bonded together, the more electronegative atom takes precedence and adopts the -1 oxidation state.
