Electric Charge

Objectives:

    1.    Name the three principle electric charges and their charges.

    2.    Describe the nature of forces that act between unlike charges and like charges.

    3.    Explain how an object can develop an overall electric charge.

    4.    Define electric field.

Resources:

    http://www.colorado.edu/physics/2000/waves_particles/wavpart3.html

Notes:

Electric Charge:

All mater is made up of atoms. 

        Is the smallest particle of an element having all of its properties

        Is made up of even smaller subatomic particles protons, neutrons and electrons

 

Subatomic particles

        Protons are found in the nucleus and have a positive charge

        Neutrons are found in the nucleus and have no charge

        Electrons orbit around the nucleus in energy shells and have a negative charge

        The mass of an atom is determined by adding the protons and neutrons

 

Charge and Force:

When charged particles come near each other, they give rise to 2 different forces.

(Remember that a force is a push or a pull)

        Force of Attraction The force that pulls objects together.  It exists between oppositely charged particles.

        Force of Repulsion The force that pushes objects apart.  It exists between same charged particles.

 

Charge and Force:

In nature, elements reside in their neutral state.

What does this mean?

        Electrons = Protons

Since the protons occupy the nucleus of the atom, the electrons must travel outside the nucleus in orbitals. 

        Electrons can be moved from one element another.

        The movement of electrons makes the particles charged.  The one that looses the electron has a relative positive charge and the one that gains the electron has a negative charge.

 

Electric Fields:

When 2 charged particles come close to each other they experience a force.

        If the charges are alike, they are repulsed from each other.

        If the charges are alike, they are attracted to each other.

The force they feel is due to electric fields around each other.