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.
Prior to being  elected President he was a US Senator from Illinois and before that  served three terms as an Illinois state senator   .   Barack Obama became president of the United States of America in  2009 and is the current president. Before he became president there  was George W. Bush and Bill Clinton. The name of the U.S. President is Barack Obama. He has held this  position since 2009.