There are three primary ways that naturally occurring radioactive isotopes decay: 1  Alpha particle emission. 2  Beta particle emission. 3  Gamma radiation emission.
President condemns Ankara attacks. The current migration crisis is a problem of the entire EU and not of a particular country, Polish President Andrzej Duda said after the end of the Visegrad Group two-day summit in Balatonfuered, Hungary, on Friday.
Image caption Lech Walesa was president of Poland from 1990 to 1995. Poland's history institute says that newly seized documents suggest former president and Solidarity hero Lech Walesa was an informer. The documents were taken earlier this week from the home of a former communist-era interior minister, Gen Czeslaw Kiszczak.