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.
This list concerns the Polish heads of state since World War I. For a list of historical monarchs of Poland from the Middle Ages to 1795 and 19th and early 20th century claimants to the Polish throne see List of Polish monarchs. 1 Kingdom of Poland (1916â1918) 2 Republic of Poland (1918â1939) 2.1 Chief of State.