berlin, german scientists willy markwald announced the discovery of a new chemical element, polonium. he recognized the priority of the french physicists marie and pierre curie who had discovered polonium 4 years earlier. mark wald had conducted his research and also discovered polonium, but later called it radiotelurium. at first he left that these were different elements, but then he admitted his mistake; polonium is very radioactive, it is not visible and does not exist in a free state. it is a decay product. uranium with a very short half-life already in in 1910, marie pierre, then already dead, succeeded in isolating this element. pure colony. powerful alpha-particle emitters later helped to discover neutrons today are being used for autonomous installations in space and deep-sea vehicles, as well as in medicine on june 7th. in 939, the film squadron number five was released on soviet screens, and in the future war with nazi germany, about how then in the ussr they represented this war with little blood and on foreign territory, according to the plot, the germans cross the border. we are ready to attack and give crushing resistance. the soviet air force destroys enemy aircraft right at the airfields, pilots