The Nature of Matter and Electricity; An Outline of Modern Views (Paperback)

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: Chap. VT] FREE ELECTRONS cannot be moved easily from one place to another within the substance. This makes the material a "poor conductor," or, as we say, a "good insulator." There is good reason for believing that the electrons within a conductor act as regards heat motion as if they were small atoms, that is, they take part with the atoms or molecules in the random vibration which appears to constitute the heat of a body. The "Evaporation" of Electrons. ? If electrons exist in large numbers within the substance of a metal it might be expected that if a metal were heated hot enough some of these would be given off into the surrounding space, after the manner in which a liquid loses molecules by evaporation. In fact this is found by experiment to be the case. The emission of electrons appears to be in every way analogous to the evaporation of a liquid (31). CHAPTER VI ELECTRONS, CHEMICAL ACTION, AND LIGHT Electrons and Chemical Action. ? It seems probable that the forces involved in chemical affinity are electrical in character, that is, the atoms which form the groups known as molecules are held together by electric attraction. Thus a molecule of hydrochloric acid is composed of one atom of hydrogen and one atom of chlorine, and the two cling together, probably because the chlorine atom has a negative charge, while the hydrogen atom has a positive one, and " unlike charges attract each other.'' When hydrogen gas and chlorine gas are put together in a vessel, heat and even light will cause them to combine suddenly and to form hydrochloric acid. That is, each atom of one kind becomes attached to one of the otherkind, forming a molecule of the new "compound," hydrochloric acid. We are on rather treacherous ground at this point, but we shall probably be not far ...