Rutherfordium

Rutherfordium is a synthetic, radioactive element made in particle accelerators, where only a few atoms can be produced at a time. Its known isotopes decay quickly; the longest-lived known one lasts about 48 minutes. Experiments on individual atoms show that its chemistry resembles that of hafnium, while many other properties, including its appearance as a bulk material, remain predictions because too little rutherfordium has ever been made to observe them directly. It has no uses outside scientific research.