![]() When marie curie was presented with an ounce of radium in 1921, it was enclosed in 110 pounds of lead. In a mix that loses about 1% of its activity in 25 years, being transformed into elements of lower atomic weight with lead being the final product of disintegration. Radium has 4 predominately natural isotopes, with the half lives being:ġ602 years (Radium 226 is a product of Uranium 238 decay), alpha emitterĦ.7 years (Radium 228 is a product of Thorium 232 breakdown), beta emitter Tritium is radioactive with a half-life of 12.32 years. Let us know!Īre you sure they weren't tritium ? That seems to be the requisite time span: You can have it Geiger counter checked to be sure. But your Big Ben (1960's) is not old enough to have the radium painted dial. My "SPUR" alarm clock circa 1949, glows only after being exposed to strong visible light or black light, so my clock probably has a phosphorous mixture of some kind. which made luminous dials of different formulas (not radium), until the late 1970's. She informs me that Westclox stopped using radium paint in the 1930's and the old Radium Dial Company (The "Radium Girls") had been bought out by the Luminous Processes Co. I wrote to the curator of the Westclox Museum in Illinois asking about this. If THIS clock face had radium paint, it would be a hundred times the amount used on a wristwatch dial. It had a faceplate nearly five inches square, with large luminous hands, and large number markers. IPad 3, iPad 4, iPad Air, iPad iPad, iPad Mini 2, iPad Mini 3, iPad Mini 4, 9.Thyratron, I may be able to shed some light on this, as I had asked the exact same question about my Westclox alarm clock, the "SPUR" model, made from 1938-1958. ![]() IPhone 12 Pro Max, iPhone 13 Pro Max, iPhone 14 Plus: 1284x2778 IPhone Xs Max, iPhone 11 Pro Max: 1242x2688 IPhone X, iPhone Xs, iPhone 11 Pro: 1125x2436 ![]() IPhone 6 plus, iPhone 6s plus, iPhone 7 plus, iPhone 8 plus: 1242x2208 IPhone 6, iPhone 6s, iPhone 7, iPhone 8: 750x1334 ![]() IPhone 5, iPhone 5s, iPhone 5c, iPhone SE: 640x1136 IPhone: iPhone 2G, iPhone 3G, iPhone 3GS: 320x480 ![]()
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