SME 301, Section 003
April 8, 2008
Self-Taught Topic Paper
It is a common misconception that many people of all ages believe that electricity
only flows in one direction. It is easy to assume that when an appliance is plugged in, the
electricity comes directly from the outlet in the wall into the appliance where it seemingly
disappears or is magically burned up. However, when one really takes the time to
understand the flow of electricity, the previous statement is hardly the case.
Big Idea One
All matter is made up of atoms. These atoms have a charge. Protons and neutrons
have a charge which is the force within a particle of matter. Most atoms have a neutral
charge which means they have an equal number of protons and electrons. However, some
atoms are either positive or negative charge. If there are more protons in an atom, it is a
positively charged atom. On the other hand, if there are more electrons, the atom will be a
negative atom. Opposite charges attract each other, while like charges repel each other.
This attracting and repelling results in a flow of electric charge which is called current
electricity. Therefore, Current
electricity is the flow of electric charge.
Big Idea Two
When this electric charge flows,
electric current travels away from like
charges, usually going from positive to negative.
The closed loop in which current
electricity is only able to travel is called a circuit. When a force is applied to an atom, this
causes electrons to move from one atom to another. This moving of electrons is what
constitutes electricity, and the force to move electric current through a circuit. When a
negatively charged object comes into contact with another negatively charged object, the
electrons in the objects will repel each other. They both now have a negative charge,
which is called charging by induction. Induction is the force that helps to move from one
atom to another, and aids in the changing of an atoms’ charge. Thus, induction can help
us determine, or even change, the direction of current electricity in a circuit. Within the
circuit, the opposites repel and the like charges attract, creating a push-pull on the atoms.
Big Idea Three
These forces help push the electrons along the path in a loop.
flows/travels within a circuit.
The negative terminal end of a battery will repel and push
negative the electrons along the path, a wire for example. The positive terminal end of a
battery will attract and pull negative electrons along the wire. Therefore, electric current
will flow from the negative terminal of the battery; travel through the light bulb, and to
the positive terminal. There are some types of materials through which electrons can
easily flow through. These are called conductors. Metals and water are examples of