Radioactivity is shown to be accompanied by chemical changes in which new types of matter are being continually produced. .... The conclusion is drawn that these chemical changes must be sub-atomic in character.

The more physics you have the less engineering you need.

If, as I have reason to believe, I have disintegrated the nucleus of the atom, this is of greater significance than the war.

You should never bet against anything in science at odds of more than about 10-12 to 1.

[From uranium] there are present at least two distinct types of radiation one that is very readily absorbed, which will be termed for convenience the α radiation, and the other of a more penetrative character, which will be termed the β radiation.

I have to keep going, as there are always people on my track. I have to publish my present work as rapidly as possible in order to keep in the race. The best sprinters in this road of investigation are Becquerel and the Curies.

Should a young scientist working with me come to me after two years of such work and ask me what to do next, I would advise him to get out of science. After two years of work, if a man does not know what to do next, he will never make a real scientist.