Static Electricity Intro

 

Unit III Electricity & Magnetism

 

Static Electricity - HyperPhysics

I.  Static Electricity - electronic charges flowing in no particular direction. (trapped in a body)

 

 

A) Electricity of the Atom

Atoms are
 ordinarily neutral

 

#p = #e-

n has no charge

p has +1 charge

e- has -1 charge

 

 

Charge electron
= 1.6 x 10-19 Coulombs
(Reference)

1. Atoms become charged by gaining or losing ...

 

 

Electrons

 

 

3 Big Rules of Electrostatics

Opposites Attract

Likes Repel

Only Electrons Move

 

Mg+2   F -1

Mg atom
Lost 2 electrons
  

F  atom
gained 1 electron

20 p , 18 e-
What's the charge?

 

 

+ 2

 

 

Why are protons never lost or gained?

 

Protons are held in the nucleus by the strongest forces in the universe

 

 

a) Ion: electrically charged particle:

 

Charge is unbalanced

 negative charge 

#e > #p

 positive charge
#p > #e

 

2. Charged objects lose their charge when grounded. (become neutral)

Bottom, round prong is the "ground"

 

When grounded:

 

Negatively charged objects ...

 

... lose electrons and become neutral.

 

Positively charged object ...

 

... gain electrons and to become neutral.

 

Electroscope