Chemical element same atomic number, or number of protons. Nuclear scientists, however, define a pure element as one that consists of only one stable isotope. For example, a copper wire is 99.99% chemically pure if 99.99% of its atoms are copper, with 29 protons each. However it is not isotopically pure since ordinary copper consists of two stable isotopes, 69% Cu and 31% Cu, with different numbers of neutrons. However, a pure gold ingot would be both chemically and isotopically pure, since ordinary gold consists only of one isotope, Au. Atoms of chemically pure elements may bond to each other chemically in
¡Cu-Cut! ¡Cu-Cut! ¡Cu-cut! was a Catalan illustrated satirical magazine, written in Catalan. Published in Barcelona between 1902 and 1912, it followed the political line marked by Francesc Cambó's Lliga Regionalista. ¡Cu-cut!, named after the cuckoo bird (), was first published on 2 January 1902 and, like El Be Negre magazine that would be published later, it steadfastly opposed Lerrouxism in Spain. Its director was Manuel Folch i Torres and most articles were written by Josep Morató i Grau, Eduard Coca i Vallmajor and Manuel Urgellès, among others such as Josep Abril i Virgili and Vicenç Caldés i Arús. The main illustrators