Structure of matter

To understand the electronic theory, it is necessary to have a clear understanding of the structure of matter. In elementary physics we are taught that matter consists of very small particles called molecules. These molecules are the smallest physically divisible parts of matter – physically divisible because they can be further subdivided by other means into smaller particles, for instance, by chemical means.

A molecule of water consists of three of these particles: two of hydrogen and one of oxygen. These smaller particles are called atoms. A molecule of water is, therefore, made up of three atoms. Similarly, any substance can always be subdivided into atoms. In some elements the atom is the same as the molecule.

The atom is still further divisible into smaller kinds of particles which are particles of positive and negative electricity. Each atom has a nucleus electrically positive and consisting of particles of which the main are protons, and the neutrons. Outside the nucleus and very far apart from it move electrons, which are negative parts of electricity. All the protons and electrons are the same in all kinds of atoms and the properties of matter are dependent on the way in which they are arranged.

The atom as a whole is neutral, since in any atom there are as many protons as there are electrons, so if one of the electrons leaves the atom, it becomes positively charged.

COMMENTARY

for instance – наприклад

which are nothing but particles – Які є нічим іншим, як частками

as a whole – у цілому

as many ... as – стільки ж ... скільки

Direct conversion of energy to electricity

Our life is revolving around electricity and its many uses. We have come to take it for granted. Much has been written on, the progress achieved in producing electricity. Most cases have dealt with direct conversion of energy to electricity. What are such processes? Are they new? Will one of the methods be used I place of the present ones for generating electricity? Will the cost of electricity be less? These and other questions will be answered and answers will depend very much on whether one is considering electricity from the standpoint of the few watts for a satellite in space or the millions of watts for even a small city.

First let us be sure we all understand what electricity is and the common means by which it is produced. We now define or electric current using the atomic theory according to which all matter is made up of tiny particles or atoms. Atoms contain electrons, which are negatively charged, protons, which are positively charged, and neutrons, which have no charge. The electrons are in other part of the atom and are free to from one atom to another. The result of the moving of these electrons in one direction is an electric current. A good conductor of electricity is a material in which the electrons readily move from atom to atom. An isolator or poor conductor on the other hand is a material in which the electrons are more strongly bound to the atom and, therefore, do not move freely. Although – the electrons pass from one atom to another, the conductor is not changed greatly by the process. Fore example, a 60 watt lamp requires the “passing of 310 (in 18) electrons per second. Although this is tremendously large number it is small in comparison to the number of electrons in an inch of even the thinnest wire.

Common sources of electricity are batteries and power plants. Energy is converted into electricity, and the chief energy source is heat from fuel. But the heat is not directly converted into electricity; it is first used to generate steam which turns the turbine operating an electrical generator. Electricity flows through transmission lines to houses, factories etc.

Now the generation of by this process is very uneconomic. Actually about 40 percent of the heat in the fuel including nuclear energy is converted into electricity, while the remaining part is generally lost in the cooling process. There has been a lot of effort and thought given to other means for generating electricity and experiments are being carried out at present in order to raise the efficiency of energy conversion.

There are some processes, which are more efficient, as high as 80%. These are generally connected with direct conversion of energy into electricity in thermionic, magneto hydrodynamic, thermoelectric and thermo photovoltaic energy converters. We have pointed out that matter is electronic in nature: “line up” the electrons so they will pass from one atom to another and an electric current will flow

COMMENTARY

our life is revolving around electricity – наше життя нерозривно зв'язане з електронікою

we have come to take it for granted – ми почали сприймати це як належне

have dealt with – мали справу з...

these questions will be answered – на ці питання будуть дані відповіді

from the standpoint – з погляду

first let us be sure – спершу упевнимося

according to – згідно, відповідно

are free to move – можуть вільно рухатися

on the other hand – з іншої сторони