Text 8 What Is An Electron?

What is an electron? It is a very small, indivisible, fundamental particle – a major constituent of all matter. All electrons appear to be identical and to have properties that do not change with time.

Two essential characteristics of the electron are its mass and its charge. Qualitatively, an electron is a piece of matter that has weight and is affected by gravity. Just as the mass of any object is defined, the mass of the electron can be defined by applying a force and measuring the resulting rate of change in the velocity of the electron, that is, the rapidity with which its velocity changes. This rate of change is called acceleration, and the electron mass is then defined as the ratio of the applied force to the resulting acceleration. The mass of the electron is found to be about 9.11  10^-28 grams. Not only the electron but all matter appears to have positive mass, which is equivalent to saying that a force applied to any object results in acceleration in the same direction as the force.

How does the other aspect, the charge of the electron, arise? All electrons have an electric charge, and the amount of charge, like the mass, is identical for all electrons. No one has ever succeeded in isolating an amount of charge smaller than that of the electron. The sign of the charge of the electron is conventionally defined as negative; the electron thus represents the fundamental unit of a negative charge.

Text 9 Electrons and electronic charges

An atom of ordinary hydrogen is composed of one positively charged proton as a nucleus and one negatively charged electron. The proton is about 1,840 times more massive than the electron. Heavier atoms are built up of protons, neutrons, and electrons. When a body is negatively charged, it has excess electrons; if positively charged, there is a deficiency of electrons.

In metallic conductors many of the electrons are free to travel about among the atoms like molecules of a gas.

When electric charges are static, they do not progress in any definite direction. Excess electrostatic charges reside on the outer surface of a conductor, and their density is greatest in regions of greatest curvature.

Text 10 Polarity

All matter is basically composed of two types of electricity: positive particles and negative particles. The negative particles are relatively light in weight and in constant motion. These orbiting particles exhibit equal and opposite electrical characteristics to the heavier particles within the nucleus.

When an atom has the same number of electrons as it has protons, it exalts no outward electrical properties. This is because the positive and negative charges are exactly balanced. Such an atom is electrically stable and is said to be neutral.

When an atom takes on an excess of electrons, it exhibits outward characteristics similar to the electron. It takes an overall negative property. This condition is called a negative change, and such changed atom is not electrically stable. A charged atom is called an ion, and if the charge is negative, it is called a negative ion.

An atom which has less than its normal quota of electrons, displays a positive polarity similar to that of the proton due to the fact that it has more positive protons than it has negative electrons. This type of atom is said to assume a positive electrical charge. Such an atom is known as a positive ion while it is in this electrically unstable condition.

These charges of atoms are the simplest examples of static electricity. We stated that atoms are influenced to accept or give up electrons.

As the name dynamic electricity indicates, this is electricity in motion. The heart of the matter is electron movement.

In electrical system, electrical pressure is needed. To maintain this pressure, a device that will move electrons in a way similar to that in which the pump moves water is necessary. The most familiar is the storage battery.