Noble gas compound Noble gas compound Noble gas compounds are chemical compounds that include an element from the noble gases, group 18 of the periodic table. Although the noble gases are generally unreactive elements, many such compounds have been observed, particularly involving the element xenon. From the standpoint of chemistry, the noble gases may be divided into two groups: the relatively reactive krypton (ionisation energy 14.0 eV), xenon (12.1 eV), and radon (10.7 eV) on one side, and the very unreactive argon (15.8 eV), neon (21.6 eV), and helium (24.6 eV) on the other. Consistent with this classification, Kr, Xe, and Rn form
Copia: Foundations of the Abundant Style book was immensely popular in England and in Europe, at least 85 editions of the book were printed in Erasmus' own lifetime, and countless more after that. Erasmus made three separate revisions to the original text, adding chapters each time. The original 1512 edition contained 153 chapters, which swelled to 206 in the final version that Erasmus completed before his death. Copia: Foundations of the Abundant Style Copia: Foundations of the Abundant Style () is a rhetoric textbook written by Dutch humanist Desiderius Erasmus, and first published in 1512. It was a best-seller widely used for teaching how to rewrite