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
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.