WITHIN THE ATOM
Let us now endeavor to analyze the atom more closely, in the light of these newer researches. We have seen that the electrons revolve round the central protons. These protons are probably composed of electrons and hydrogen nuclei. The total central “sun”—to use the astronomical analogy—is known as the nucleus. The relative sizes of these bodies may be appreciated when it is stated that they have been compared to the sizes of the planets, relative to the distances separating them from the sun. Vast spaces exist, therefore, within the atom, in which the electrons revolve. Yet the atoms themselves are inconceivably small! The following quotation from Bertrand Russell’s “A. B. C. of Atoms” will perhaps make this clear. He says:
“It will help us to picture the world of atoms if we have, to begin with, some idea of the size of these units. Let us begin with a gramme of hydrogen (1/453 of a pound), which is not a very large quantity. How many atoms will it contain? If the atoms were made up into bundles of a million-million, and then into a million-million of these bundles, we should have about a gramme and a half of hydrogen. That is to say, the weight of one atom of hydrogen is about a million-millionth of a million-millionth of a gramme and a half. Other atoms weigh more than the atom of hydrogen, but not enormously more; an atom of oxygen weighssixteen times as much, an atom of lead rather more than 200 times as much.Per contra, an electron weighs very much less than a hydrogen atom; it takes about 1,850 electrons to weigh as much as one hydrogen atom.”