1. Electrostatics Fundamental Forces Model of the atom Unit of charge
Charge is conserved
Charge is carried by the electron

2. Research Challenge
You have 5 minutes to find out what you can!
What are the four fundamental forces of the universe?
Briefly describe how two of them work.

3. 4 Fundamental Forces of the Universe
What causes gravitational force?
MASS!
Gravity
Electromagnetism
Nuclear Strong Force
Nuclear Weak Force
What causes the electric force?
CHARGE!

4. S.I. Fundamental Units q C x m t s kg charge coulomb Quantity
Quantity symbol
Unit
Unit symbol
distance x
meter m
time t
second s
mass
kilogram kg
charge q
coulomb C
Make a table showing symbols, etc.

5. The Atom Electrons Neutron Proton
charge in a proton = charge in an electron - -
Electrons
Attract AND Repel!
Unlike charges attract (+, -)
Like charges repell (+,+ or -, -)
Proton
Neutron
Net Charge atom is
neutral if number of protons = number of electrons
“+” if the atom is missing electrons (it is called an ion)
“-” if the atom has extra electrons + +
nucleus
Charge is conserved not created or destroyed, moves from place to place
Bohr Model of the Atom

6. One atom says to the other atom,
“I’m missing an electron!”.
The other atom says, “Are you sure?”
The first atom replies…
“I’m positive”

7. How Does Charge Move? It is the electron that carries charge
In a solid, the nucleus is fixed in place. + + + + + + + + + + + + + + + + + +
It is the electron that carries charge + +