Static electricity

Charge
As fundamental to electricity and magnetism as mass is to mechanics

Charge is a concept to quantitatively relate particles to each other, in terms of how they affect each other. Charge is represented by Q.

The basic idea - like charges repel (2 negatives or 2 positives). Opposite charges attract.

Charge is measured in terms on units called coulombs (C). A coulomb is a huge amount of charge - the charge due to 6.2 x 10^18 protons.  That's 6.2 billion billion protons.  A lot of charge, even though this takes up a small amount of actual space..

The charge of a proton is tiny: 1.6 x 10^-19 C.

(By the way, the number above is called the fundamental charge unit (represented by the letter e).  It is the reciprocal of the number of protons in one coulomb.)

Similarly, the charge of an electron is the same value but negative (by definition): -1.6 x 10^-19 C

The Charge of a neutron is 0 C, or neutral.

How particles interact with each other is embodied in a physical law called Coulomb's law:

F = k Q1 Q2 / d^2

Or, the force tha exists between 2 particles is proportional to the product of charges divided by the distance squared. A proportionality constant is used to make units work out nicely.

Note that this is an inverse square law like gravitation.

The big 3 of particles are:

Proton
Neutron
Electron

However, of these onl the electron is "fundamental," meaning that it can't be further subdivided. Protons and neutrons can be broken up into quarks.

There are 6 types of quarks - up, down, top, bottom, charm, strange. The names mean nothing.

They are exotic particles which typically do not exist alone in nature.

A proton is: 2 ups and a down quark.
A neutron is: 2 downs and an up quark.

Well over 100 particles exist, but few are fundamental.

FYI:  an up quark has a charge of 2/3 e (that's the charge of 2/3 of a proton), and a down quark has the charge of -1/3 a proton (which is like 1/3 of an electron).