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Het uiterst radioactieve radium is het zwaarste bekende aardalkalimetaal dat chemisch gezien vrijwel identiek is aan barium. Hoewel het metaal van zichzelf helder wit of zilverkleurig is, verandert dat bij contact met lucht in donkergrijs tot zwart. Radium is luminescent (zwak blauwe kleur) en reageert met water onder vorming van radiumhydroxide .
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.
Radium ( lat. radium) on maa-alkalimetalleihin kuuluva alkuaine, jonka kemiallinen merkki on Ra, järjestysluku 88 ja CAS-numero 7440-14-4. Se on radioaktiivinen, hopeanvalkoinen, pehmeä metalli, jonka elektronegatiivisuus on 0,9 ja ensimmäinen ionisoitumisenergia 510 kJ/mol. Sen löysivät Pierre ja Marie Curie vuonna 1898 Joachimsthalin (nyk.
Radium dials are watch, clock and other instrument dials painted with luminous paint containing radium-226 to produce radioluminescence. Radium dials were produced throughout most of the 20th century before being replaced by safer tritium -based luminous material in the 1970s and finally by non-toxic, non-radioactive strontium aluminate –based photoluminescent material from the middle 1990s.
Radium compounds are compounds containing the element radium (Ra). Due to radium's radioactivity, not many compounds have been well characterized. Solid radium compounds are white as radium ions provide no specific coloring, but they gradually turn yellow and then dark over time due to self- radiolysis from radium's alpha decay . [1]
Le radium est un métal alcalino-terreux présent en très faible quantité dans les minerais d' uranium. Il est extrêmement radioactif, la demi-vie de son isotope le plus stable ( 226 Ra) étant de 1 600 ans. Il fournit du radon comme produit de désintégration. Marie Curie et son mari Pierre le découvrent en 1898 par extraction de la ...
Radium silih tunggil datu kimia antuk simbol Ra miwah wilangan atom 88. Punika datu kaenem ring seka 2 saking tabél périodik . Radium murni mawarna putih masawang pérak, menawi aluh maréaksi sareng nitrogén (nénten oksigén ) ri kala kena udara, ngawentuk lapisan pamukaan ireng radium nitrida (Ra 3 N 2 ).
