Stronger in what sense? It would really help if you clarify the question.
Radium is a decay product of uranium.
Radium has not its own minerals; radium exist in extremely low concentrations in uranium and thorium ores.
Uranium and radium, and a number of others, are natural elements found in the ground, and they are radioactive.
Uranium is the most reactive.
Radium exist in very small concentrations in uranium ores.
Radium exist in uranium ores but in very low concentrations.
Because radium is a decay product of uranium or thorium.
Separation and refining of radium and polonium from uranium ores by different chemical technology processes.
Radium is a decay product of uranium and is therefore found in all uranium-bearing ores. (One metric ton of pitchblende yields 0.0001 grams of radium). Radium was originally acquired from pitchblende ore from Joachimsthal, Bohemia, in the Czech Republic. Carnotite sands in Colorado provide some of the element, but richer ores are found in the Democratic Republic of the Congo and the Great Lakes area of Canada, and can also be extracted from uranium processing waste. Large radium-containing uranium deposits are located in Canada (Ontario), the United States (New Mexico, Utah, and Virginia), Australia, and in other places.
Radium exist in very low concentrations in uranium and thorium ores.
Absolutely none. Radium is element #88, while uranium is element #92. They are two completely different entities. If you are referring to uranium ores, it is a different story. The ratio is about 3 metric tons of uranium to 1 gram of radium. Oxygen and other elements are also present in uranium ore. http://en.wikipedia.org/wiki/Uranium#Oxides
Radium exist in extremely low concentrations in uranium and thorium ores.