Difference Between Isotope and Radioisotope


Main Difference

The main difference between Isotope and Radioisotope is that Isotope is the element having the same proton number but a different atomic mass number, whereas Radioisotope is also actually the isotopes but in unstable form and undergoes in a chemical decay to stabilize itself.

Isotope vs. Radioisotope

Isotope is defined as the atom of the same element having the same atomic number, but the different atomic mass number; on the other hand, the radioisotope is also the isotopes but in unstable form and produce radiation to stabilize itself. Isotopes are may be present in two forms, i.e., stable or unstable; on the flip side, radioisotopes are present in an only unstable form. In isotopes, the stable isotopes don’t emit radiation, but the unstable isotopes emit radiations, whereas all the radioactive isotopes emit radiations.


Isotopes can occur in the form of elemental or combination form; on the other hand, radioisotopes are present in one form for a short period. Isotope in stable form does not have a half-life, but unstable have half-life; on the flip side, all the radioactive elements have a half-life period. An isotope of stable forms having a stable nucleus but unstable don’t; on the other side, all the radioactive isotopes have an unstable nucleus. Isotopes of stable form do not contain radioactivity but unstable show this property; however, all the radioisotopes elements show this property.

Isotopes are used in an application where radioactivity is not used, whereas radioisotopes used in radioactive applications such as DNA analysis. Stable isotopes do not include this half-life property, and unstable have very long half-life property; however, in radioisotopes, half-life property is very short. Examples of isotopes are, i.e., hydrogen such as protium, deuterium, and tritium, whereas the example of Radioisotopes is, i.e., radium, rubidium, etc.


Comparison Chart

It is the number of atoms having the same atomic number but the different atomic mass numbers.It is the isotopes but in unstable form and emit radiations.
It is present in two forms, i.e., stable or unstable.It is only present in an unstable form.
Stable isotopes do not emit the radiations and present in a stable form, but unstable emit to become stable.Radioisotopes emit radiation every time to become stable.
It is present in the form of an elemental of combinational form.It is present in only one form for a very short period.
It is used in those places where radioactive materials are not allowed to use.It is used in a radioactive method such as DNA analysis.
Half-Life Property
Some isotopes have usually do not half-life property, but in some isotopes, it is very long.The half-life property is very short in radioisotopes.
Stability of Nucleus
Isotopes nucleus is very stable and does not radiate energy.Radioisotopes nucleus is very unstable and decays very often.
It is used in our daily life treatments and application.It is used in the treatment of cancer, which is cured by radiations.

What is Isotope?

Isotope is the atom that has the number of atoms, i.e., the same atomic number, but a different atomic mass number. It is of two types, i.e., stable and unstable. Stable isotopes having a stable nucleus and do not radiate the energy to stabilize itself. Stable isotopes do not radiate the energy, but unstable isotopes radiate the energy to become stable.

The isotopes are present in combinational or elemental form. It has a vast application. It is used in the place where radioactive elements are not used allowed, for example, in different medical treatments. The stable isotopes usually do not have any half-life property, but unstable isotopes have very long half-life property.

The stable isotope does not emit the radiations to stabilized itself. Isotopes also consider as an atom with a specific mass number. For example, isotopes of hydrogen are protium, deuterium, and tritium.

What is Radioisotope?

It is the isotope that is in unstable form and emits radiations to stabilize itself. These type pf isotopes are only present in radioactive form. Radioisotope emit radiations every time to stabilize itself. It is present only in one form for a short period. Radioisotope decays itself every time. It has a vast use in medical treatment, i.e., DNA analysis. The half-life property of radioisotopes is very small.

The radioisotope is only present in one form, and their half-life period is very short. Every radioisotope has a very unstable nucleus. Radioisotopes don’t have any types or kinds. Radioisotopes also have numerous applications in different fields because of its property of radioactive decay, which causes the emission of radioactive rays from the nucleus.

The radioactive decay of radioisotopes is of three types, i.e., alpha radiations, beta radiations, and gemma radiations. Radioisotopes are high radiations and used in high power of the generations.

Key Differences

  1. An isotope of different atoms in an element having the same atomic number but different mass numbers, whereas radioisotope is also the isotopes but in an unstable condition.
  2. Isotope is of two forms, i.e., stable or unstable; on the other hand, the radioisotope is of only one form, which is an unstable isotope.
  3. Isotope is present in two forms, i.e., elemental or combinational form; conversely, radioisotopes are present only in one single form.
  4. An isotope of stable form does not produce radiations; on the flip side, radioisotope becomes stable by radioactive decay.
  5. Isotope is used in non-radioactive treatments, whereas radioisotope is used in radioactive treatments like in the treatment of cancer patients.
  6. Isotope doesn’t have the property of half-life period, whereas radioisotope has the property of half-life property.


The above discussion concludes that the isotope is an atom of elements having the same atomic number but a different atomic mass number, whereas radioisotope is also isotope but in an unstable form.

Harlon Moss

Harlon currently works as a quality moderator and content writer for Difference Wiki. He graduated from the University of California in 2010 with a degree in Computer Science. Follow him on Twitter @HarlonMoss