1. The discovery of two radioactive elements, radium and polonium, belongs to scientific discovery and does not belong to the scope of patent application.
2. However, the industrial extraction method of these two elements can be patented, and there is later Curie therapy (using laser rays to kill cancer cells).
As for why pierre curie didn't apply for a patent for the above technology, it was because pierre curie died in a car accident in 1906, and the separation and extraction of radium was completed by his wife Marie Curie and Debin in the following 19 10, and the application of laser line in medical treatment was even later.
postscript
Madame Curie didn't apply for a patent because she said, "That's against the scientific spirit. Scientists' research results should be published publicly, and others should develop them without any restrictions. "Besides, radium is good for patients, so we should not use it for profit.