This will not be on the
This will not really be
covered in class!  
DO NOT need to
know this!
In the beginning of this chapter atoms were the smallest
unit of matter, they were thought to be indivisible and the
primary unit of all matter.  That is still true......to a point.

Atoms, were then discovered to be made of smaller
particles, first electrons, then protons and finally
neutrons.  Most of the atom was then defined as being
empty space.

One then had to ask....could the pieces of the atoms be
divided into smaller parts?  What were the protons,
neutrons and electrons made of?

Here we venture into the strange world of Quarks.  We
must learn a few new definitions and read things that may
not really make sense to us now......but that is the
excitement of physics.

After this page many will as the next logical question, what
are quarks made of?   At this point there is not even a
guess, but then, if we knew it all what would you have to
Baryons and Mesons
Baryons are massive particles which
are made up of three quarks
. This
class of particles includes the proton,
the neutron and other particles we
haven't mentioned.  Baryons are
different from mesons in that
are composed of only two quarks.

Baryons and mesons are included in
the overall class known as
(the particles which interact by the
strong force).
Protons and Neutrons
Along with neutrons, protons make up
the nucleus, held together by the
strong force. The proton is a baryon
and is considered to be composed of
two up quarks and one down quark.

The neutron is a baryon and is
considered to be composed of two
down quarks and one up quark.
This means that our current
model of a helium atom looks
similar to this.  Notice that the
nucleus is made of two
protons (u,u,d) and two
neutrons (d,d,u). Circling
them is the two electrons.
Quarks - Beyond the Atom
Why is this here?
The purpose of this page is for those student who just have
to know.  Curiosity demands that they learn a bit more
about what makes up these atoms that make up
everything.  Even more so, to know what lies beyond the
Besides, it's really cool!