8 - The Character Concept: Adaptationalism to Molecular Developments

Abstract

This chapter defines the element, which is the fundamental classificatory term of chemistry, and the classifications it provides rest on a more fundamental set of classifications in atomic theory. It also defines Faraday's experiments, which suggests that in electrolysis the weight of an element is directly proportional to electricity required to liberate it. Elements which did not combine with any other element in a chemical reaction are all gases. For each of these inert gases, the next heavier element is always a metal with a shiny luster that conducts both electricity and heat, and reacts vigorously with water to form basic solutions and with hydrochloric acid to form salts. These elements are the alkali metals. For each of the inert gases, the immediately lighter element is a nonmetal, a poor conductor, and reacts with hydrogen to form acids. This group of elements is the halogens. The elements between each alkali metal and the halogen which follows it show a gradation of properties such as electrical conductance and acidity.