Also Known As Static Electricity Chemistry Refresher Atom the basic unit that makes up all matter Made up of protons neutrons and electrons Chemistry Refresher Proton Part of an atom that has a positive charge ID: 273315
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Slide1
Electrostatics
Also Known As
Static ElectricitySlide2
Chemistry Refresher
Atom
the basic unit that makes up all
matter
Made up of protons, neutrons, and electronsSlide3
Chemistry Refresher
Proton
Part of an atom that has a positive charge
Located in the nucleus
Does not leave the nucleus of the atomSlide4
Chemistry Refresher
Neutron
Part of an atom that has a neutral charge
Located in the nucleus
Does not leave the nucleus of the atomSlide5
Chemistry Refresher
Electron
e-
Part of an atom that has a negative charge
Located in the outer part of the atom
Can leave the atomSlide6
Chemistry Refresher
Because electrons can leave atoms,
e
lectrons
can move from one object to another when touchedSlide7
Static Electricity
A
stationary electric charge that is built up on a material.
Examples
Door knob shock
“Static cling”
Lightening
“Bad Hair Day”Slide8
Charge
q
A characteristic of a unit of matter that expresses the extent to
which
it
has more or fewer electrons
than
protons.Slide9
Charge continued
In atoms, the electron carries a negative
charge and
the proton carries a positive charge. The two types of charge are equal and opposite.
The amount of charge carried by an atom is always a multiple of the
elementary charge
, that is, the charge carried by a single electron or a single proton
.Slide10
Elementary Charge
e
the
electrical charge carried by a single electron measured in CoulombsSlide11
Coulomb
the standard unit of electric charge in the International System of Units (
SI
). 1 C is equal to approximately 6.24 x 1018
e
1 e
= 1.60 x 10
-19
CSlide12
Force
A push or a pull
Contact forces (friction, tension, etc.)
Non-contact forces (gravity, electromagnetic forces, etc.)
Measured in
Newtons
(N)Slide13
Just as we calculated the gravitational force between two planets earlier in the year, our study of static electricity will involve calculating the electromagnetic force of attraction or repulsion of charged objects.
Electromagnetic force is surprisingly similar to gravitational force.Slide14
Think back to our unit on gravitational force. When calculating the amount of force between two planets, we used the following formula:
Where
F
g
was the gravitational force, G was the gravitational constant, m
1
was the mass of the first planet, m
2
was the mass of the second planet, and d was the distance between them.
Slide15
Now we will be calculating electrostatic force
u
sing the following equation:
Fe = K(q1q2)/d2
Where F
e
is the electrostatic force, K is Coulomb’s constant (9 X 10
9
), q
1
is the charge of the first object, q
2
is the charge of the second object, and d is the distance between the two objects.Slide16
Coulomb's Law
states
that the electrical force between two charged objects is directly proportional to the product of the quantity of charge on the objects and inversely proportional to the square of the separation distance between the two objects
.In other words, Fe
= K(q
1
q
2
)/
d
2Slide17
Practice Problem
Consider
a thundercloud that has an electric charge of
24.0 C near the top of the cloud and -24.0 C near the bottom of the cloud. These charges are separated by about 3000 m. What is the magnitude of the electric force between these two sets of charges?Slide18
Practice Problem
A pith ball with a charge of
+
8 x 10-8 C is brought to a distance of .0005 m from a second pith ball with a charge of -6 x 10-8 C. What is the magnitude and the strength of the electric force between the two charges?