Ionic order

“ One real advance which has been attained by means of the theory of ionization, and it is of extreme significance and of far-reaching importance, consists in the discovery that electrification or the possession of charge, instead of being a casual or accidental property, temporarily imparted by friction or other process, is a fundamental property of matter. According to this newer conception of matter, the fruit of the ionic theory, the ultimate parts of matter, are electrically charged particles. ”

“ They may well be connected in some way with solvent molecules, and there are several indications that an ion consists of an electrified part of the molecule of the dissolved salt with an attendant atmosphere of solvent round it. The conductivity of a salt solution depends on two factors— (1) the fraction of the salt ionized; (2) the velocity with which the ions, when free from each other, move under the electric forces. [2] When a solution is heated, both these factors may change. The coefficient of ionization usually, though not always, decreases; the specific ionic velocities increase. ”

“ For the ionizing work, i.e., the work necessary to eject the electron completely from the normal state and thus make the atom into a positive ion, the Bohr theory gives a value of the same order of magnitude as the so-called “ionization potentials” which have been found by experiment for various gases. An exact correspondence between theory and experiment could for hydrogen not be attained with certainty, because the hydrogen atoms in hydrogen gas under ordinary conditions always appear united in molecules. ”

“ But, on the other hand, if a few drops of acid be placed in the vessel with the platinum, bubbles of hydrogen appear, and a current flows, zinc dissolving at the anode, and hydrogen being liberated at the cathode. In order that positively electrified ions may enter a solution, an equivalent amount of other positive ions must be removed or negative ions be added, and, for the process to occur spontaneously, the possible action at the two electrodes must involve a decrease in the total available energy of the system. ”

“ For up to this time the only type of ionization known was that observed in solution and here it is always some compound molecule like sodium chloride (NaCl) which splits up spontaneously into a positively charged sodium ion and a negatively charged chlorine ion. But the ionization produced in gases by X-rays was of a wholly different sort, for it was observable in pure gases like nitrogen or oxygen, or even in monatomic gases like argon and helium. Plainly, then, the neutral atom even of a monatomic substance must possess minute electrical charges as constituents. ”

“ A special feature, however, wanting with carbon, is that compounds with one atom only of the element in question have been obtained as antipodes. A second observation of some interest is that the compounds in question are electrolytes and that, as in solutions, where they are split up into ions, activity must be due to the last, the ionic complex, for instance, RiR 2 R s S, must cause optical rotation. ”

“ So far as the negative ion is concerned, the situation at the moment seems to be in favor of the atom-ion theory. There has recently developed strong evidence [19] that although in some very pure gases, such as helium, argon, and even nitrogen, the negative electron cannot find attachment at all, when it does attach so as to form ions of the mobility mentioned above, it carries with it thereafter but a single molecule. ”

“ So far back as 1850 he also suggested a view which, in a modified form, is of fundamental importance in the modern theory of ionic dissociation, for, in a paper on the theory of the formation of ether, he urged that in an aggregate of molecules of any compound there is an exchange constantly going on between the elements which are contained in it ”

“ The passage of electrons from filament to plate at certain voltages produces changes in the gas, known as 'ionization.' Ionization is the manifestation of a rearrangement of the constituent electrons of the gas atoms which occurs, in low vacuum tubes, if other factors of causation remain constant, at known voltages within a range of from 20 to 30, but varying somewhat with different gases. The atom, according to present day scientific theory, is composed of an electrically positive nucleus, around which revolve at high speeds electrically negative electrons. ”

“ Any charged particle, irrespective of its energy, moving in any medium—air, water, soil, or living tissue—creates ion pairs at the rate of about one per 32 electron-volts. A one-million-electron-volt particle produces about 30,000 ion pairs before losing all of its energy. (When it does lose its energy, if it is a positively charged particle, it will pick up enough electrons to become neutral. An alpha particle, for example, will become an ordinary helium atom; a proton will become an atom of hydrogen.) ”

“ Ehrenhaft as well as ourselves, it would be necessary to assume that there exist in the air an infinite number of different kinds of ionic charges corresponding to the infinite number of possible radii of drops, and that when a powerful electric field drives all of these ions toward a given drop this drop selects in each instance just the charge which corresponds to its particular radius. ”

“ What gets away isn’t a sodium atom for it has one too few electrons; and what remains behind isn’t a chlorine atom for it has one too many electrons. We call these new groups “ions” from a Greek word which means “to go” for they do go, wandering off into the spaces between the water 20molecules. Fig. 3 gives you an idea of what happens.
You remember that in an atom there are always just as many protons as electrons. In this sodium ion which is formed when the nucleus of the sodium atom breaks away but leaves behind one planetary electron, there is then one more proton than there are electrons. ”

“ In fact, electric forces will drive the positive and negative ions through the air in opposite directions, thus giving rise to an electric current. If the ionization process is not steadily continued, the air gradually loses its conductivity, since the positive and negative ions recombine into neutral atoms or molecules. Ionization can be produced by flames, [Pg 78] since the air rising from a flame contains ions. A strong ionization can also be brought about by X-rays and by ultra-violet rays. ”

“ The ionization potential of an atom is the energy in volts that is required in order to remove the outermost electron to infinity. The excitation potential corresponding to any particular spectral series is the energy in volts that must be imparted to the atom in the normal state in order that there may be an electron in a suitable electron orbit for the absorption or emission of that series. Several different excitation potentials are usually associated with one atom. The ionization potential and the excitation potentials are collectively termed the critical potentials. ”

“ If, for example, it is desired to place a positive electron upon a given drop the latter is held with the aid of the field fairly close to the negative plate, say the upper plate; then an ionizing agent—X-rays or radium—is arranged to produce uniform ionization in the gas between the plates. Since now all the positive ions move up while the negatives move down, the drop is in a shower of positive ions, and if the ionization is intense enough the drop is sure to be hit. In this way a positive charge of almost any desired strength may be placed upon the drop. ”

“ The potential difference required to produce saturation will, other circumstances being the same, increase with the amount of ionization, for when the number of ions is large and they are crowded together, the time which will elapse before a positive one combines with a negative will be smaller than when the number of ions is small. The ions have therefore to be removed more quickly from the gas when the ionization is great than when it is small; thus they must move at a higher speed and must therefore be acted upon by a larger force. ”

“ Here, then, is an absolutely direct proof that the ion must he endowed with a kinetic energy of agitation which is sufficient to push it up to the surface of the drop against the electrostatic repulsion of the charge already existing on the drop, and when we remember that an ion is nothing but a molecule containing an unneutralized electrical charge, it will be clear that we have here direct proof that the molecules of the gas are endowed with motion. ”

“ This result seems to show with considerable certainty that the negative ions in gases ionized by X-rays or similar agencies carry on the average the same charge as that borne by the univalent ion in electrolysis. When we consider the work on the positive ion, our confidence in the inevitableness of the conclusions reached by the methods under consideration is perhaps somewhat shaken. ”

“ The formation of a hydrogen molecule may also be supposed to occur when a positive hydrogen ion, i.e., a hydrogen nucleus, and a negative hydrogen ion, i.e., a hydrogen nucleus with two electrons, are drawn together by their mutual attractions. The forces of attraction would be much stronger than in the first example given, and the formation of a neutral molecule would not take place in the same way. More energy would also be released, but the final result will be the same. ”

“ Protons repel each other, and electrons repel each other, but an electron and a proton attract each other. Every atom is a structure consisting of electrons and protons. The hydrogen atom, which is the simplest, consists of one proton with one electron going round it as a planet goes round the sun. The electron may be lost, and the proton left alone; the atom is then positively electrified. But when it has its electron, it is, as a whole, electrically neutral, since the positive electricity of the proton is exactly balanced by the negative electricity of the electron. ”

“ As the fall of intensity of the lines of neutral atoms after maximum is the result of the progress of ionization, it would be expected that the lines of the ionized atom would appear while those of the neutral atom were still quite strong, and that the one series would rise in strength as the other decreased. The lines of the neutral atom may persist over a large part of the range of the ionized lines. ”

“ We have reason to believe that there are in each molecule of ordinary protoplasm at least 450 atoms of carbon, 720 atoms of hydrogen, 116 of nitrogen, 6 of sulphur, and 140 of oxygen. Nerve-plasm is still more complex.
Recent discoveries have only increased the wonder and potentiality of the cortex. Each atom has proved to be a remarkable constellation of electrons, a colossal reservoir of energy. The atom of hydrogen contains about 1,000 electrons, the atom of carbon 12,000, the atom of nitrogen 14,000, the atom of oxygen 16,000, and the atom of sulphur 32,000. ”

“ Thus, one atom of nitrogen unites with three of hydrogen, one of carbon with four of hydrogen, and so on. Every substance has, therefore, what is called its ‘quantivalence,’ or power of uniting with it a greater or less quantity of other atoms, and conversely that of replacing in combinations other atoms, or groups of atoms, the sum of whose quantivalence equals its own. Thus, one atom of carbon, which has four poles, combines with four atoms of hydrogen or chlorine, which is unipolar, but with only two of oxygen, which are bipolar ”

“ In one case we unite an atom of chlorine to an atom of sodium and thereby produce a molecule of common salt. In another case we unite an atom of oxygen to two atoms of hydrogen, and the resulting combination is an invisible molecule of ordinary water.
It has always seemed to me very strange how some men have difficulty in regard to these combinations. I have heard a man ask how two different gases, hydrogen and oxygen, when united, should form a liquid, and not a gas. I wish you could see things as we see them. The atoms are neither gaseous, liquid, nor solid ”

“ But if one ion, say the anion, travels faster through the liquid than the other, the end of the solution from which it comes will be more exhausted of salt than the end towards which it goes. If we assume that no other cause is at work, it is easy to prove that, with non-dissolvable electrodes, the ratio of salt lost at the anode to the salt lost at the cathode must be equal to the ratio of the velocity of the cation to the velocity of the anion. ”

“ The electrons, when they are propagated in a gas, can ionise the molecules of this gas and unite with the neutral atoms to form negative ions, while positive ions also appear. There are likewise produced, at the expense of the gas still subsisting after rarefication within the tube, positive ions which, attracted by the cathode and reaching it, are not all neutralised by the negative electrons, and can, if the cathode be perforated, pass through it, and if not, pass round it. ”

“ Lowered pressure increases the degree of ionization. The tendency of the atoms to lose electrons by thermal ionization should depend solely on their energy supply, and should thus be independent of the pressure. The total absorbing power of the gas will, however, depend on the number of suitable atoms that it contains, not upon their rate of formation. The number of suitable ionized atoms present at any moment in the atmosphere is a function not only of the rate at which ionization proceeds, but also of the rate of recombination. ”