Rutherfordium ended the chain when it decayed by spontaneous fission.
From the sciencedaily.com
Finally, after another two and a half minutes, rutherfordium 265 decayed by spontaneous fission.
From the sciencedaily.com
That, in turn, lasted a third of a second before becoming seaborgium-269, which made it three minutes and five seconds before emitting an alpha particle to become rutherfordium-265.
From the latimes.com
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A radioactive transuranic element which has been synthesized
Rutherfordium is a chemical element with the symbol Rf and atomic number 104. On the periodic table of the elements, it is a p-block element and the first one of the transactinide element. It is member of the 7th period and also belongs to the group 4 elements. ...