Dubnium not have enough experimental data to back their claim. After collecting more data, JINR proposed the name "nielsbohrium" (Ns) in honor of the Danish nuclear physicist Niels Bohr, a founder of the theories of atomic structure and quantum theory. When LBL first announced their synthesis of element 105, they proposed that the new element be named "hahnium" (Ha) after the German chemist Otto Hahn, the "father of nuclear chemistry", thus creating an element naming controversy. In the early 1970s, both teams reported synthesis of the next element, element 106, but did not suggest names. JINR suggested establishing an international committee
Otto Hahn transferred from Vienna to Berlin. So began the thirty-year collaboration and lifelong close friendship between the two scientists. After the physicist Harriet Brooks had observed a "radioactive recoil" in 1904, but interpreted it wrongly, Otto Hahn succeeded, in late 1908 and early 1909, in demonstrating the radioactive recoil incident to alpha particle emission and interpreting it correctly. The physicist Walther Gerlach described this as "a profoundly significant discovery in physics with far-reaching consequences". Rutherford in Manchester wrote in a letter to his mother: "He is doing the best work in Germany at present." In 1910, Hahn was appointed professor by