One of two or more atoms with the same atomic
number (the same chemical element) but with
different atomic weights.
A unit of work or energy equal to 107 ergs.
An uncharged elementary particle with a mass slightly
greater than that of the proton and found in the
nucleus of every atom heavier than hydrogen.
The intensity of electromagnetic radiation power per
unit area expressed as watts/cm2.
An elementary particle with a single positive electrical
charge and a mass approximately 1,837 times that of
unstable atomic nucleus, usually accompanied by the
emission of ionizing radiation.
A radioactive isotope. An unstable isotope of an
element that decays or disintegrates spontaneously,
beta particles, and alpha particles.
The treatment of disease with gamma radiation from a
source located at a distance from the patient.
A unit of power equal to one joule per second.
The distance between any two similar points of two
consecutive waves for electromagnetic radiation.