Sketch of an Atom
have two parts - an inside called the nucleus that has a positive
electric charge, and the outside that is a cloud of electrons with a
are made of protons that have a positive charge and neutrons that have
no charge. Every nucleus must have at least 1 proton to attract
Table of Elements
Periodic Table is an organized list of all elements. The number of
protons in an atom's nucleus is its element number.
and neutrons are made of quarks: two Up quarks and one Down quark
make a proton; two Downs and one Up make a neutron.
are the particles from which all matter is made. There are 12
elementary fermions, 6 quarks and 6 leptons, arranged in three
"generations", each with 2 quarks and 2 leptons.
arise when two particles of matter exchange another type of particle -
a boson - as shown on the right, where a particle shown in yellow emits
a boson shown in black which is absorbed by another particle shown in
green. This exchange causes a force between the yellow and green
particles. Each force has its own bosons.