# Electric Charge
- Charges come in two varieties, positive and negative.
- Net charge is the *algebraic sum* of an object's charges
- Protons and electrons have the same magnitude of charge ($1e$)
	- The SI Unit of charge is the *Coulomb* (abbreviated C)
	- The smallest discrete quantity of charge is $\frac{1}{3}e$.
- In an isolated system, the net charge will always remain constant.

# Electric Force
- Two charges will exert a force on each other along the line joining them.
	- The magnitude of this force is proportional to the *product of the charges* and inversely proportional to the to the $\sqrt{dist}$.
	- The equation to determine the force between two charges is as follows:
	$$ \vec{F_{12} = \vec{r}k\frac{q_1q_2}{r^2}} $$
		- $\vec{r}$ is a unit vector pointing from charge 1 to charge 2
		- $k$ is Couloumb's constant, or $8.99 * 10^9 \frac{Nm^2}{C^2}$ 
		- $q_1$ and $q_2$