(Glossary of Terms)
Ampere – The unit used to measure the electric current or
flow of electrons through an electrical conductor or circuit.
Atom- The smallest particle of an element that can exist
either alone or in combination; it is also known as the
building block of matter. An atom can be electrically
neutral or have a positive or negative charge. If it has either
a positive or negative charge, it is called an ion. The charge
is determined by the number of electrons (which carry a
negative charge) compared to the number of protons (which
carry a positive charge). The negative charges (electrons) of
the atom can move from one object to another for certain
materials (see Conductor).
Battery- A source of electrical energy that is created by a
chemical reaction and pushes electric charges within a circuit.
Battery Terminal- The connecting points or locations on a
battery where the electrical charges leave or enter the battery.
Circuit- A path through which electricity flows.
Closed Circuit- A completes electrical circuit or path
through which electricity or current can pass or flow.
Conductor- Materials through which electrical current can
flow. Copper is a good conductor. Most electrical wires are
Electric Motor- A device that converts or changes electrical
energy into mechanical energy.
Electric Charge- An electrical property of an atom, described
as either positive or negative.
Electric Current- A flow of electrons; the quantity of
electrons that moves through the circuit. Electric current is
measured in amperes (amps).
Electric Discharge- The jumping of electric charges between
Electrical Energy- Form of energy created by the flow of
electrons; this energy allows the completion of work.
Filament- A wire or similar part of a light bulb through
which electricity flows; it glows from the heat generated by
passage of the electrical current.
Power Generator- A device that changes or converts
mechanical energy into electrical energy.
Insulator- Materials that do not easily carry or allow the
passage or flow of an electric current. Examples of insulators
are glass, rubber, plastic, and air.
Ion –Any atom or molecule that carries an electrical charge,
either positive or negative.
Magnet- An object that pulls or attracts iron or steel and has
a force around it. The pull or attraction is strongest at its ends
or poles, and they are labeled North and South.
Magnetism- The force around a magnet.
Ohm- The unit used to measure the resistance to the flow of
electrons or electric current.
Open Circuit- A circuit or electrical path that is broken or
incomplete, and so electricity cannot flow through it.
Parallel Circuit- An electrical circuit in which the electricity
can follow more than one path. It is a circuit that connects
several objects or resistances in a way that allows each
resistance to have its own path. This is the way appliances and
lights are connected in homes, so they do not all have to be
on at once.
Resistance- A measure of how well electricity moves through
a material. Insulators have high resistance; conductors have
low resistance. Resistance of an object is measured in ohms.
Series Circuit- A circuit in which all the lights or resistors
are connected in sequence, or one after the other, forming a
single path through which the electricity can flow. Batteries
in a flashlight and in small, portable radios are frequently
connected in series.
Static Electricity- Electricity that is motionless or at rest; it is
produced by rubbing two objects together, such as a resin rod
and a piece of silk fabric, or a balloon against a piece of wool
Switch- A device that allows an electrical circuit to be opened
Voltage – The force or push, given by a battery or generator
that moves electrons from one place to another in an electric
circuit or conductor.
Volts – The unit used to measure voltage.
Watts- A unit for measuring how quickly or how much an
appliance or other device uses electricity.