RADIATION TERMS AND DEFINITIONS
Atomic number - The number of protons in the nucleus of the atom.
Since the protons are positively charged, enough negatively charged
electrons are collected around the nucleus to neutralize or charge
balance the atom. These protons and electrons give the atom its
unique chemical nature.
Atomic mass - The sum of the
weights of both the neutrons and the protons in the atom.
Electron - A small negatively
charged particle that surrounds the nucleus with a mass about 1/1800
that of the proton . Beta particles are energetic electrons ejected
from a radioactive nucleus.
Element - the most basic physical
substance composed of all the same type of atoms. Each atom will
have the same number of protons. The number of neutrons can differ.
Isotope - Atoms with the same
number of protons, but differing in the number of neutrons present
in the nucleus. Most elements have more than one isotope.
Neutron - An electrically neutral
particle found in the nucleus with a mass almost that of the proton.
In the fission process, neutrons are liberated.
Nucleus - The densely packed
kernel of the atom containing protons and neutrons. The diameter
of the nucleus is 100,000 to 200,000 smaller than the whole atom.
Photon - The smallest
unit of light. The photon is often described as a electromagnetic
wave or wave packet. Light photons from red to blue in the visible
spectrum have increasing energy. X-rays and gamma rays are energetic
photons with thousands to millions of times the energy of light
photons.
Proton - An electrically
positive particle found in the nucleus of the atom. Each proton
is balanced by the charge of an electron surrounding the nucleus.
The electrically neutral atom has the same number of negative electrons
as positive protons.
