An introduction to electronics

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#Pages 2 and 3 of chapter 1 of this pdf book are missing!!! Book starts off well but without the missing pages the rest of the material is incomprehensible. I can see that although the characters from page two show through the paper on page one the next two pages were not scanned and therefore the page numbering jumps from page one to page four. The individual that scanned this book needs to go for retraining before being trusted to scan any more books. Found the 2 missing pages so I'm adding them here: _____________________________________________________ 2 THE CONSTITUTION OF MATTER pressed between the anode and the cathode (for comparison, the voltage between the wires of an ordinary house circuit is about 115 volts), a small part of the cathode ray passes through the tube in a concentrated line of light and produces a luminous spot on a fluorescent screen at the end. This type of cathode-ray tube is used in the modern television receiver and is discussed in another chapter. When the concentrated cathode ray is made to impinge upon one side of a small windmill placed in the tube, the windmill rotates and shows that the ray contains a moving substance, possessing mass, which was emitted by the cathode. A magnet placed near the tube causes the ray to be deflected in the same direction as that of an electric current flowing from the anode to the cathode. Since the direction of an electric current is always assumed to be the same as the flow of positive charges through a circuit, any substance de- flected by a magnet in the same manner but flowing in the opposite direction must consist of negative charges of electricity. Discovery of the Electron Various experiments show that the moving substance consists of discrete particles moving from the cathode to the anode (and be- yond if the anode is perforated) and when the voltage is very high at a velocity as high as 62,000 miles per second (one third of the velocity of light), each particle bearing a negative electric charge of 4.80 x 10^(-10) statcoulomb. A statcoulomb is a charge of elec- tricity which, if placed at a distance of 1 centimeter from another charge of electricity of the same magnitude and sign, and both concentrated at a point, would repel it with a force of 1 dyne. If the reader is not conversant with the relative magnitude of metric and British units of measurement, a comprehensive table of con- version factors will be found on page 94. The notation 10^(-10), as explained in the Preface, means 1 divided by 10) multiplied by itself 10 times; in this case, meaning one ten-billionth. The mass of these particles has been measured and found to be 9.04 x 10^(-28) gram at rest. The mass increases with the velocity and becomes infinite at the velocity of light. A particle bearing the above negative charge of electricity and with the stated mass is called an "electron." Its diameter is indefinite but is probably about 10^(-13) centimeter. _____________________________________________________ THE HYDROGEN ATOM 3 Discovery of the Proton From the above observations we may conclude that, among other things, matter contains minute negative charges of electricity of definite mass but increasing with velocity. In the cathode ray we do not see the moving electrons but the consequence of their interrupted motion when they collide with molecules of gas or water vapor which thereupon radiate light. Since matter in general is not electrically charged and we may draw negative charges from any neutral body, it is evident that all matter must contain compensating positive charges of equal number and strength as the negative charges. If we drill a hole in the cathode of a cathode-ray tube and provide another evacuated space at the exterior opening of this hole we see another ray in this space, called a " canal ray." Deflection of this ray by a magnet shows that it contains slow—speed positive particles, the smallest of which car- ries a charge of 4.80 x 10^(-10) stateoulomb like that of the electron. Its mass, however, is 1838 times that of the electron and its diameter is about 10^(-16) centimeter. This positively charged and denser par- ticle is called a "proton." It has a mass of 1.66 x 10^(-24) gram and a density over a million million times that of the electron. The Hydrogen Atom We have known for some time from chemical sources that the lightest atom among the elements is hydrogen with a mass of 1.66 X 10^(-24) gram. Since this is almost precisely the mass of a proton (it would require more significant figures beyond the 1.66 to show the slight difference), it must be concluded that a hydrogen atom contains one proton and one electron. Although the com- posite hydrogen atom is usually neutral (without charge) we may always pull the electron out of it so it must be assumed that each charge maintains its identity. We know that aggregate positive and negative charges are pulled together with a force equal to their product divided by the square of the distance between them. What then prevents the proton and the electron from plunging together in the hydrogen atom? It was first suggested that the electron must revolve about the proton as shown in Fig. 3, at such a distance and velocity that the outward centrifugal force associated with such revolution will equal _____________________________________________________

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