Conductors and Insulators

The charges of electrons and protons are the same in magnitude but will have an opposite sign. All charged particles are just multiples of these simple positive and negative charges. The symbol q is used to describe an electric charge in physics. The SI unit for charge is the coulomb or the letter C. The number of protons it takes to make a coulomb of charge is about 6.25 x 1018 protons or electrons.

From a molecular standpoint, there is no infrastructure to the electron. There is a substructure inside the proton, however. It appears that there are sub-particles called quarks inside protons that are believed to carry fractional charges. Quarks will have charges that are either -1/3rd or +2/3rds. At no time is it considered that charge can be created or destroyed. This is called the law of conservation of charge, which is similar to the law of conservation of energy and the laws of conservation of angular and linear momentum.

According to the law of conservation of charge, there is charge conservation at all times. The opposite of an electron is called a positron or anti-electron. The total charge will always be zero. In the same vein, there is matter and antimatter, which means that, when matter is created in a particle accelerator, antimatter must also exist so that the charge is zero. When matter and antimatter are brought together, they completely annihilate one another, being converted into energy, which goes by the letter E.

CONDUCTORS AND INSULATORS

There are some things that easily allow for the transfer of charges. Salty water will carry charge through it as will metallic substances. Electricity moves not through the transfer of positive charge but always through the transfer of negative charge or “free electrons”. Any substance that has the ability for free electrons to flow through them will be called conductors. Superconductors are things that will allow the movement of charge without a loss of energy, which is not the case with conductors, which will lose energy because the electrons will collide with fixed atoms and molecules.

Salty water and other salt-containing liquids will conduct electricity because they contain ions. Ions are positively-charged or negatively-charged atoms or molecules in salt solutions. The anion will have a negative charge, while the cat-ion will have a

positive charge. In all cases, even when electricity moves through a salt solution, there will be an equal number of anions and cations in the solution.

In addition, there are other substances that are considered insulators because they do not conduct electricity. This is because insulators will have fixed electrons and fixed protons; the electrons will not be able to move as easily through an insulator as is true of a conductor. Pure water is considered an insulator as is dry salt mixtures; however, the mixture of the two in solution is considered a conductor.

Charge can be passed directly touching positively-charged substances with negativelycharged molecules in electroscopes. It is not necessary, however, to transfer the electrical charge of something to something else through direct touching. The charge can be passed through close proximity as long as there is no insulator between the two. This is called the induced polarization of neutral objects. Polarization is the separation of charges in any object that is overall a neutral object. There is no difference in charge across the total area just a difference in charge across the object. This is shown in figure 106:

Figure 106.

Neutral objects can be attracted to any charged object. Think of a plastic comb rubbed through the air that can pick up neutral objects that aren’t very heavy. This happens because a charged object can polarize a neutral substance, making it charged on one side