Page 26 - Bebop to The Boolean Boogie An Unconventional Guide to Electronics Fundamentals, Components, and Processes

Atoms, Molecules,

and Crystals

Matter, the stuff that everything is made of, is formed from atoms. The heart
of an atom, the nucleus, is composed of protons and neumons and is surrounded
by a “cloud” of electrons.’ For example, consider an atom of the gas helium,
which consists of two protons, two neutrons, and two electrons (Figure 2-1).
It may help to visualize the electrons as orbiting the
nucleus in the same way that the moon orbits the P = Proton
N = Neutron
earth. In the real world things aren’t this e = electron
+ve = positive charge
simple, but the concept of orbiting , -ve = negativecharge
\
electrons serves our purpose here. / \ \
Each proton carries a single / /‘ \ \
+ve :--.
\
positive (+ve) charge, and each ---
0 \
electron carries a single negative 1 / \ \
I I \
(-ve) charge. The neutrons are \ \ ‘. I I
neutral and act like glue, holding ‘--+-- -______---
,L
I
the nucleus together and resisting \ \ / ;
the natural tendency of \ \ / /
\ .---/
/
the protons to repel each other. \ ,
/
Protons and neutrons are approxi-
Figure 2-1. Helium atom
mately the same size, while electrons
are very much smaller. If a basketball
were used to represent the nucleus of a helium atom, then, on the same scale,
softballs could represent the individual protons and neutrons, while large
garden peas could represent the electrons. In this case, the diameter of an
electron’s orbit would be approximately equal to the length of 250 American

We now know that protons and neutrons are formed from fundamental particles called quarks,
of which there are six flavors: up, down, charm, strange, top (or truth), and bottom (or beauty).
Quarks are so weird that they have been referred to as “The dreams that stuff is made from,” and
they are way beyond the scope of this book.