Marie Curie was able to begin work. Their mutual passion for science brought them increasingly closer, and they began to develop feelings for one another. Eventually Pierre Curie proposed marriage, but at first Skłodowska did not accept as she was still planning to go back to her native country. Curie, however, declared that he was ready to move with her to Poland, even if it meant being reduced to teaching French. Meanwhile, for the 1894 summer break, Skłodowska returned to Warsaw, where she visited her family. She was still laboring under the illusion that she would be able to work in her
Curie gram of radium. According to Bertram Boltwood, Marie Curie thought that 'the use of the name "curie" for so infinitesimally small [a] quantity of anything was altogether inappropriate.' The power in milliwatts emitted by one curie of radiation can be calculated by taking the number of MeV for the radiation times approximately 5.93. A radiotherapy machine may have roughly 1000 Ci of a radioisotope such as caesium-137 or cobalt-60. This quantity of radioactivity can produce serious health effects with only a few minutes of close-range, unshielded exposure. Ingesting even a millicurie is usually fatal (unless it is a very short-lived