Isotopes In Infrared spectroscopy
What is an isotope?
An isotope is defined as one of two or more atoms of the same element that have the same number of protons in their nucleus but different numbers of neutrons. (Oxford dictionary of Chemistry)
In simple terms isotopes are atoms that have the same atomic number but different atomic masses.
The name isotope comes from the Greek language where isotope means, "equal place". The term equal place is significant as it shows that although the atoms have different masses they are still only one element and only occupy one place on the periodic table.
It is only the number of neutrons that alters in an isotope and as it is the atomic number that determines the identity and properties of the element, an element can have different masses as long as they have the same number of protons (atomic number).
The different number of neutrons in the isotopes of an element affect there mass but not their chemical property, as the number of neutrons does not affect the number of electrons an atom needs to achieve a full outer shell of electrons.
How are isotopes specified?
An isotope is named by writing its mass number after the name of the element, e.g. Carbon-12, and Carbon-13. This is usually written with the mass number as a superscript to the left of the chemical symbol 12C and 13C.
Author: Vicki Wright (document modification date: 28th May 2004)