The concept of isotopes is introduced to high school chemistry students. However, it is important for graduate students in all fields of chemistry to understand what they are and how to apply their uses in research. Here you will find information about isotopes and mass spectrometry.
Isotopes
Mass Spectrometry
Magnetic Resonance Imaging
There are other uses of isotopes, and this section will discuss an imaging process called magnetic resonance imaging, or MRI. This imaging technique is used to take pictures of the insides of the human body. Doctors use MRI to locate tumors in people. This technique takes advantage of the nuclear properties of certain isotopes. Sometimes, a patient is simply placed in the instrument, and the image is taken. Other times, if the location of the tumor is known, a radioactive compound is injected into the tumor, and then the image is taken. Dr. Ralph Mason visited Texas A&M University and gave a lecture on MRI technology. In the following three clips, he discussed the magnetic properties of hydrogen, a radioactive isotope of fluorine:
, and radioactive isotopes of arsenic.
Nuclear Chemistry
Isotopes must be understood in the study of nuclear chemistry. Unstable isotopes of an element may decompose into other elements and release energy. Here is an example. Uranium is one of the most widely know elements in nuclear technology. A radioactive isotope of this element (uranium-235) will break down into thorium-231 and helium-4 according to the following reaction.
The helium atom in this reaction contains no electrons. Therefore, it has a charge of 2+, and is also called an alpha particle. Notice that the number of protons and neutrons is additive.
92 = 90 + 2
235 = 231 + 4Here is another classic decomposition reaction. Phosphorus-32 will change into sulfur-32, and an electron and a gamma ray are emitted.
An electron is also called a beta particle. A gamma ray is a photon of light that contains a lot of energy, and is very dangerous.
