This is an awesome question that hits upon many
fundamental concepts about materials science and
You are indeed correct in saying that in general a
pure element has equal number of protons and
An important thing to note is that between
isotopes, material properties do in fact change,
but probably not the ones that immediately come to
mind. I'll try to answer your questions in chunks,
because this is indeed a huge area of active
research that involves many disciplines!
Does the proton have particles within it,
sort of like DNA, that define the properties of an
Your analogy of a proton having some of sort of
DNA is great. A proton turns out is indeed
composed of even smaller particles, known as
quarks. Particle physicists seemed to have
had a lot of fun naming quarks, as they have
peculiar names like up, down, charm, or strange.
A proton has been found to be made of two up
quarks and one down quark.
This is part of the bigger picture known as the
Model , which was a model created in the late
20th century as a attempt to formulate a grand
unified model for all the subatomic particles and
interactions between these particles (i.e.,
electromagnetic, strong, weak, and gravitational).
(It is in fact from the Standard Model that the
gravitational force-carrier particle, the
Higgs boson , was predicted to exist.)
Here is a nice chart that summarizes the
Do these particles, if they exist, have a
relationship with the electron?
From my understanding, there are two major types
of subatomic particles- fermions and bosons.
The difference between the two is that fermions
have half-integer spin and bosons have integer spin.
What does that mean? The concept of
spin is enough for another answer, but you
can think of it as an intrinsic property of the
particles, much like its mass or charge. Basically
this difference in spin means fermions and bosons
are subject to different kinds of interactions
when interacting with other particles, and this
has extremely important consequences for
It turns out both protons (and neutrons) and
electrons are composed of fermions. Protons
are composites of quarks and electrons are
leptons. And these both fit into the larger
picture of the Standard Model. One major
difference between the two is that leptons do not
experience the strong force, i.e., the force that
keeps the nucleus together.
You might ask, why is universe composed of
such particles? Why fermions and bosons?
We don't know the reason, only that experiments
have shown that the Standard Model is a pretty
good start to understanding. There are several
ideas for why the universe is made the way it is,
the most famous being
string theory .
Returning to changing material properties between
isotopes and how electrons fit into the picture.
There are two main concepts to understand about
1) Charge neutrality
In general, it's not required that the number
of electrons and protons are the same for a
particular atom. What is important is that the
system overall is charge neutral, or at least
compensated by charge elsewhere. For example, in
table salt NaCl (sodium chloride), you have Na+
and Cl- ions and they are arranged in such a way
that the substance overall is charge neutral. It
just turns out that for a pure element, this is
generally thought of as equal number of protons
and electrons for a particular atom.
By loosening this constraint, lots of different
materials are possible (e.g., alloys, compounds,
2) Materials properties from electrons
This leads us into the idea of how materials
properties (e.g., hardness, conductivity,
magnetism) arise from level of atoms. Solid-state
physics is an entire field dedicated to this, and
is what I'm researching in now!
Electrons are responsible for a huge array of
material properties- electrical conductivity (and
conversely resistivity), elastic modulus (how
stiff something is), magnetism, optical properties
such as reflectance- and chemical properties-
corrosiveness, reactivity, acidity, chemical
But material properties can also differ between
isotopes. Because the mass of the atom has
significantly changed, this can affect the thermal
conductivity. Most notably, the radioactive
lifetime of an element, such as in carbon, is
useful for figuring out how old artifacts are!