Geology Reference
In-Depth Information
Atoms themselves are composed of smaller,
subatomicparticles
called neutrons, pro-
tons, and electrons. Figure 5-1 is a diagram of atomic structure, including the location of
each different subatomic particle type. Protons and neutrons are located in the nucleus
at the center of the atom. In each atom, the electrons surround the nucleus, organized
into orbital shells. The innermost orbital shell of any atom contains no more than two
electrons; the second orbital shell contains no more than eight; and each of the outer
shells, while chemically stable with eight electrons, can hold more.
Figure 5-1:
The
parts of an atom.
The number of protons in an atom's nucleus determines which element the
atom is. For example, an atom with six protons is an atom of the element carbon.
An atom with seven protons is an atom of nitrogen.
Getting comfortable with the periodic table
The
periodic table of elements
lists the known elements in order of their
atomic number,
which is their number of protons. Each square on the periodic table provides you with
all the information you need to know about that element and how it will interact with
other elements. Figure 5-2 illustrates what the different numbers for each element on the
periodic table represent.
