Unit 3 Fields ­ Graviational, Electrical, Magnetic
Review of Grade 11 Electrostatics
Review of Matter
1. All matter is composed of_______________ or ________________
Our ideas about the nature of atoms have progressed over the last two centuries (and continue to develop today).
• John Dalton introduced a new form of the ancient Greek idea of atoms at the beginning of the nineteenth century. • In 1897, J.J. Thomson discovered the _______________ and suggested the ______________ model of the atom.
• In 1911, Rutherford suggested that ___________________________________________
• _______________________________________________________________________.
• In 1914, Bohr modified Rutherford's model by__________________________________
• __________________________________________________________________.
2. Atoms contain _____________, ______________ and _____________. Of these three subatomic particles, only the __________ (positively charged) and the __________ (negatively charged) are considered charged particles. A neutral object has an _________ number of protons. A charged object has an ___________ number of electrons and protons.
(see hyperlink for more information) <http://www.broadeducation.com/htmlDemos/AbsorbChem/HistoryAtom/page.htm>
Electrostatics
Static means __________________
Electrostatics: is the study of the phenomena arising from what seems to be ______________________ electric charges.
Current Electricity refers to ________________________________________________
_____________________________________________________________________
Objects become charged by friction
Objects are considered neutral because __________________________________
When two objects rub against each other and each object has a different level of attraction for their electrons, electrons from _____________________________________
The electron affinity series helps predict which object will gains ____________ and becomes _______________ and which object loses _______________ and becomes __________.
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Charge is distributed uniformly in a conductor
As an object becomes charged because the number of ___________ does not equal the number of ___________ then the excess charges will distribute themselves uniformly in the object. This means...
Electric potential
Electric potential refers to the build up of charge. The greater the charge differences, the greater the potential for danger. Damage, however, will only happen when ___________
______________________________________
______________________________________
______________________________________
Induced Charge Separation
Induced charge separation refers to the influence another object can have on a conductor. As a charged object is brought near a conductor, the charges will ______________________________
________________________________________
________________________________________
________________________________________
http://phet.colorado.edu/en/simulations/category/physics
Medium
Definition ­ the surrounding environment, substance. Examples ______________________________
Conductors vs. Insulators
The bonding nature (structure) of a material affects its ability to be influenced by a charge. A conductor ____________ a charge (electrons) to move within the material rather easily where an insulator restricts any internal movement of charge (electrons). An insulator ______________ the movement of particles including electrons.
<http://hyperphysics.phy­astr.gsu.edu/hbase/electric/conins.html>
Humidity
Humidity is a measure of the amount of ________________ in the air. Water is a better ______________ then air and Lightning is more likely to happen when the humidity is high ­ or raining. Static electricity is a greater concern in ___________ weather because the water in the air is ________ likely to grab onto free electrons.
Since protons are fixed in the __________of an atom, electrons are the charge which become influenced and ______________. But, because charges obey the law of opposites, we can analyze charges through the movement of either positive or negative charges, ignoring their connection to the atom.
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