While trying to make somewhat of a timeline of the history of ionizatig radiation, i am wondering about the following questions:
The first photoelectrical effect was found 1839 by Alexandre Becquerell - the photoelectrical effect and therefore UV-light, would be the first ionization radiation. Is that right?
While i am quite sure about it for electromagnetical radiation, i am not sure about particle radiation. Was there any ionizating particle radiation before the discovery of uran-radiation by Antoine Becquerell?
A source for proof would be quite a nice extra, thanks!