sekundina
Sekundina is a hypothetical element proposed in the early 20th century. Its existence was theorized by some chemists who believed it might fill a gap in the periodic table, specifically between selenium and tellurium. The name "sekundina" was derived from the Latin word "secundus," meaning "second," suggesting its position as a second element in a particular group.
Despite considerable effort by researchers at the time, including attempts to synthesize or isolate it, sekundina
The development of more sophisticated analytical techniques and a deeper understanding of nuclear reactions eventually led