Circuit Basics: Charges and Electricity

(Previous topic: "Introduction" Posted on February 10, 2012) All things, that are said to be matter, fill up (occupy) some space and have mass. Mass is the amount of atoms or molecules that matter is built from. Molecules are simply the joining or bonding of atoms. An understanding of the structure of atoms (atomic structure) and the ways they bond helps with understanding electricity; however, it isn’t necessary. Atoms are made from three types of particles (subatomic particles). Only hydrogen atoms have two types. These subatomic particles are neutrons, protons, and electrons. Neutrons are not charged (neutral), protons have positive charges (+), and electrons have negative charges (-). Atoms do not depend on neutrons to become charged. Atoms with equal number of electrons and protons are also neutral and don’t have an electrical charge. Atoms have negative charges (called negative ions) when there are more electrons than protons, and atoms have positive charges (called positive ions) when there are more protons than electrons. Negative ions push away (repel) other negative ions. Electrons repel other electrons and negative ions. Electrons leave negative ions and atoms that don’t want some electrons. The electrons move toward (are attracted to) positive ions and towards atoms that want more electrons. Electrons can travel through certain materials to bond with atoms that have positive charges. Electrons can easily flow through some materials, such as copper and iron. Materials that allow the flow of electrons are called conductors, and this flow (current) of electrons is called electricity. Materials such as plastic and wood, that don’t allow electrons to easily flow through them, are called insulators. Materials that permit the flow of electrons but slow down (resist) the electrical current are called resistors. Positive ions also repel other positive ions; however, ions cannot move through hard (solid) materials. (The next topic will be posted later.)

Please use the following links to navigate to two videos on this topic:

• http://youtu.be/_YQnt5-0wl8
• http://youtu.be/XkK2n8Xcqb0