Experiences

Basic notions from electrecity I.

Mária Fabianová

Slovakia

Lower Secondary School

Chemistry

Teaching in class

Direct

Students have very vague ideas about the electricity since primary schools. They do not realise that the electrical phenomenon had already known the early man as a flash because it is transition of electrical current through gas. Obviously he did not think of it as of the electrical phenomenon but as a rage of gods. A flash caused the first fire what had fundamental impact on development of human civilization.
If we want to talk about basic concepts we have to return to structure of atoms. With no obvious reason students cannot remember what three particles are in an atom and what their charge is. I have to repeat to them that proton has a positive charge, electron a negative charge and neutron a neutral charge. We use letter Q for electric charge and its unit is one coulomb (C). Hub size of the proton and electron is the same, only the sign is different, it is 0,000 000 000 000 000 0001602 C. This charge is considered to be the smallest possible and which cannot be further divided even though recently it is also suggested as a structure of nuclear matter I stay behind this conclusion. Each atom has the same number of electrons and protons therefore it is electrically neutral. When the balance between protons and neutrons is broken and ion is formed. Positively charged particle is called cation and negatively charged one is called anion.


I have also films about this subject but it is nothing revolutionary, it is the same as if I had drew on the blackboard.
According to the conductivity of substances we divide them into conductors, non-conductors and semiconductors. Non-conductors are also called insulators. They are equally needed as conductors because they prevent from electric shock. Even thousands years ago people protected themselves from lightening by using skin of animals.
The best electrical conductors are metals what results from their inner structure. They contain freely movable electrically charged particles – electrons. Actually their flow is electrical current. Liquids are also conductors thanks to ions as in the gases.
In the 19th century when people knew how to electrify bodies electrical phenomenon became fair attractions. Few people held their hands, minimal current was released and they were happy from unknown shaking.
On the other hand, when electricity had to be used in households, people were afraid of it and refused to use it. Nowadays we are dependent on it.
I consider this experience to be positive.