Group 4 element doses and does not play any natural role inside the human body. Zirconium powder can cause irritation, but only contact with the eyes requires medical attention. OSHA recommendations for zirconium are 5 mg/m time weighted average limit and a 10 mg/m short-term exposure limit. Only limited data exists on the toxicology of hafnium. Group 4 element Group 4 is a group of elements in the periodic table. It contains the elements titanium (Ti), zirconium (Zr), hafnium (Hf) and rutherfordium (Rf). This group lies in the d-block of the periodic table. The group itself has not acquired a trivial name; it
The Periodic Table of Science Fiction The Periodic Table of Science Fiction The Periodic Table of Science Fiction is a collection of 118 very short stories by science fiction author Michael Swanwick. Each story is named after an element in the periodic table, including the then-undiscovered element 117. The stories were commissioned to run on Eileen Gunn's The Infinite Matrix but were published in the Sci Fiction section of SciFi.com, between 2001 and 2003. The stories were published as they were written, about which Swanwick said, "It made the sequence into a kind of performance art, something akin to being a trapeze artist, which is a