This book brings together for the first time the key facts about the chemical elements that make up the world around us. These data are often needed but difficult to track down. Now they have been brought together in a systematic and easy-to-use format, arranged alphabetically, element by element. All the numerical data are given in SI units, together with a simple key chapter explaining them and how to convert to other units. Under each element, information is provided on such topics as chemical properties, thermodynamics, x-ray coefficients, reduction potentials, ionization energies, biological activities, and atomic spectra. Thirty-two tables of properties of elements, arranged in order of element and in order of ranking, conclude the book.