Home Chapter 2 Models of the Atom
Models of the Atom
Book - Chapter 2

The number of protons in the nucleus of the atom allows us to identify atoms by their atomic number. For example, on the periodic table, hydrogen, with an atomic number of one, is the lightest and simplest atom. The atomic weight of the atom is the sum of the mass of all particles, so the atomic weight of hydrogen would be 1.00794 atomic mass units with the proton making up the bulk of that weight.

Hydrogen is both the lightest gas and the most abundant element in the universe. Hydrogen exists in water as well as all living organisms, and it also exists in stars in a plasma state, so when poets tell you are composed of star dust, they are not far off.


Atomic number represents the number of protons in the nucleus, and, if it’s a neutral atom, the number of electrons orbiting the nucleus.

Atomic weight is the mass of one atom of an element.






An atom with four shells of electrons. There are four valence electrons in the outermost shell.


While all of these models visualize and describe some of the characteristics of atoms, the science of quantum theory currently tells us that an electron’s position and velocity cannot be absolutely determined.

Quantum theory also tells us we can visualize electrons as waves of energy surrounding the nucleus, and instead of drawing planetary models, we can use the science of mathematics to map the probability of electron movement. Imagine, instead, probability clouds surrounding the nucleus.

While probability clouds are indeterminate, what is determined is that protons in the nucleus are positively charged, neutrons are neutral with no charge, and electrons circulating around the nucleus are negatively charged. Scientists once surmised that the atom was composed of just neutrons, electrons, and protons, but they have now confirmed that the atom has many more particles than once thought--with even more to be discovered.

New particles are discovered by accelerating atoms and smashing them together in  a supercolliders or particle accelerator. The results of the “crash of atoms” allow scientists to look at and analyze the constituent parts, and in this process, discover new particles that reveal the nature of our universe. Imagine things crashing together at high speeds and coming apart. It would stand the reason that at super high speeds we would get closer to their constituent parts.


Supercolliders are machines that accelerate and smash particles together using very powerful magnets.


With supercolliders, scientists have now discovered that neutrons and protons in the nucleus are also divisible and are composed of particles called quarks. There are six types of quarks: top quarks, bottom quarks, charm quarks, up quarks, down quarks, and, yes, strange quarks.

We call the particles that quarks are made of hadrons, so protons and neutrons are types of hadrons. I have heard physicists say, that if you claim, “I understand the atom,” you are probably not a very good physicist, as much is left to discover and confirm.


Quarks are the particles that make up protons and neutrons. Each of these particles is composed of three quarks. Up quarks have a charge of 2/3, while down quarks have a charge of –1/3. A proton, with an overall charge of 1, has two up quarks and one down quark (2/3 + 2/3 + -1/3 = 1). Neutrons, with a 0 charge, have two down quarks and one up quark (-1/3 + -1/3 + 2/3 = 0). (Murray Gell-Mann)


It is illuminating of the creative process itself to see the progressive visualization and drawings of the atom and understand how knowledge and discovery is a progressive and evolutive process of experimentation, imagination and visualization.



If you can visualize and imagine your idea by progressively refining “what it is” you are describing, you will be rewarded with the evolution of your idea.

It is wise to keep a sketchbook of your ideas and continue to refine them, as the reward may be a new invention, artwork, or way of seeing. Knowledge is cumulative, and the process of ideation, creation and invention requires that fundamental knowledge that is known, be pushed to the background, so that new connected ideas may arise.