3.4 Nomenclature of Elements with Atomic Numbers > 100

The naming of the new elements with very high atomic numbers are so unstable that only minute quantities, sometimes only a few atoms of them are obtained. Their synthesis and characterisation, therefore, require highly sophisticated costly equipment and laboratory. Such work is carried out with competitive spirit only in some laboratories in the world. For example, both American and Soviet scientists claimed credit for discovering element 104. The Americans named it Rutherfordium whereas the Soviets named it Kurchatovium. To avoid such problems, the IUPAC has made the recommendation that until a new element’s discovery is proved, and its name is officially recognised, a systematic nomenclature be derived directly from the atomic number of the element using the numerical roots for 0 and numbers 1-9. These are shown in Table 3.4. The roots are put together in order of digits which make up the atomic number and “ium” is added at the end. The IUPAC names for elements with \(Z\) above 100 are shown in Table 3.5.

• Thus, the new element first gets a temporary name, with symbol consisting of three letters. Later permanent name and symbol are given by a vote of IUPAC representatives from each country. The permanent name might reflect the country (or state of the country) in which the element was discovered, or pay tribute to a notable scientist. As of now, elements with atomic numbers up to 118 have been discovered. Official names of all elements have been announced by IUPAC.

Example 3.1: What would be the IUPAC name and symbol for the element with atomic number 120?

Answer: From Table 3.4, the roots for 1,2 and 0 are un, bi and nil, respectively. Hence, the symbol and the name respectively are Ubn and unbinilium.