Electricity electricity = phenomenon involving electric charges electrical force is similar to gravity in that it is inverse

proportional to the square of the distance between charges charges are assigned positive or negative values like charges repel, opposites attract modern atomic theory explains the origin of electric charge

to the existence of small negative particles (electrons) and small positive particles (protons)

an atom can gain electrons in its outer shells to gain negative charge or

lose electrons increasing the strength of the proton charge (positive)

Electric Fields: the mathematical problem of describing motion of electric charges leads to

the development of the field concept the use of fields (as in electric field, gravitational field, force field) is

mathematical tool to describe physical events the field itself is not observable, only its effects (motion)

The discovery of Coulomb's law, and the behavior or motion of charged particles near other charged particles led to the development of the electric field concept.

A field can be considered a type of energy in space, or energy with position. A field is usually visualized as a set of lines surrounding the body, however these lines do not exist, they are strictly a mathematical construct to describe motion. Fields are used in electricity, magnetism, gravity and almost all aspects of modern physics.

An electric field is the region around an electric charge in which an electric force is exerted on another charge.

Magnetism: related to electricity, is the phenomenon of magnetism magnetism results from the motion of electric charges, although historically

we know of the behavior of magnetic fields from bar magnets magnetic fields deflect moving charges or other magnets

magnets have north and south poles, similar to positive and negative charge, but poles can never be separated

Magnetism is the phenomenon associated with the motion of electric charges.

 Basic magnetism is the existence of magnetic fields which deflect moving charges or other magnets. Similar to electric force in strength and direction, magnetic objects are said to have `poles'. However, magnetic objects are always found in pairs, there do not exist isolated poles in Nature.

The most common source of a magnetic field is an electric current loop. The motion of electric charges in a pattern produces a magnetic field and its associated magnetic force.

 Electricity and magnetism are now known to be components of the unified theory of electromagnetism.

Electromagnetism: in a key development for modern physics, electricity and magnetism were

`unified' into electromagnetism

the connection develops from the fact that an electric current (the flow of electrons in a metal) produces a magnetic field

Faraday shows that a changing electric field produces a magnetic field and, vice-versus, a changing magnetic field produces an electric current

Maxwell completes the theory with a full mathematical description of the relationship between electric and magnetic fields = electromagnetism