Isotopes are atoms of the same element that have different numbers of neutrons. There are two main types: stable isotopes that do not decay over time, and unstable or radioactive isotopes that decay by emitting radiation. Isotopic signatures can be used to trace the origins and migration of materials. Examples of isotope uses include carbon-14 dating of fossils, uranium-235 as nuclear fuel, and radioactive isotopes for medical purposes like cancer treatment and diagnosing thyroid problems.

3. • Each atom has the same number of electrons
as protons, but in the case of isotopes they
are a little bit different; they have the same
number of electrons and protons but different
numbers of neutrons. But isotopes have the
same atomic number and also the same
position in the periodic table but they have
different atomic masses.

4. • Isotopes are members of a family of an
element that all have the same number of
protons but different numbers of neutrons.
The number of protons in a nucleus
determines the element's atomic number on
the Periodic Table. For example, carbon has six
protons and is atomic number 6.

6. Stable Isotopes
• These types of isotopes will decay over time
and will turn into another isotope or another
element. Most elements which are found in
nature are made of stable isotopes.

7. Unstable Isotopes
• They emit radiation and are also called
radioisotopes. When radioisotopes undergo
radioactive decay, the initial isotope is called
the parent isotope and the atoms produced by
the reaction are called daughter isotopes.

8. • The technique used to measure the number
and proportion of isotopes in matter and trace
their origin history and source of origin is
called nuclear technology.

9. • With these measurements, the experts
understand what volume of certain vitamins
are absorbed by the body, and the number of
fertiliser plants take up and many more.

10. Example of Isotopes
• Carbon 12
• Carbon 14
• Uranium 235
• Uranium 238
• Deuterium

11. • Isotopic signatures are commonly known as
fingerprints, because they are similar to
human fingerprints and are used to track and
trace. They are found
in water, land, plants and animals. By tracing
these fingerprints, scientists can evaluate:

12. • the migration of species on land and in water
• food chains and dietary changes of animals
• geographical and botanical provenance of
food
• the age and quality of water bodies
including groundwater aquifers
• origins of water and atmosphere pollution

13. • For example, the naturally occurring isotope
carbon-14 present in water is used to
understand the age of water and other
organic materials.

15. Uses of Isotopes
• Carbon 14 is an isotope of carbon which is used
in carbon dating. The amount of carbon present
in the fossils helps in calculating the age of fossils.
• The isotopes of Uranium such as U-235 are used
as a fossil fuel in nuclear reactors.
• Radioactive isotopes are generally used for
medicinal purposes, for example, for detecting
cancerous cells.
• Iodine is an isotope of carbon which is used in the
treatment of goitre.

16. • Isotopes of iodine are used to treat goitre
disease and isotopes of iodine are also used to
locate tumours of the brain and liver.
• Cobalt 60 is the radioactive isotope used in
treatment of cancer.
•

17. • There are more than 3000 known
radioisotopes. They are the unstable form of
an element. They emit different levels of
radiation, which makes them useful
in medicine, industry, agriculture, radiopharm
aceutical sciences, industrial
applications, environmental
tracing and biological studies.

18. • One use of radioisotopes is to manage cancer
and chronic diseases using radioisotope
therapy, which treats cancerous cells in a safe
and effective manner. Other uses include
creating better health care products by
removing or neutralising chemicals, bacteria
and toxins which pose a hazard.

19. • Only a small fraction of the isotopes are known to
be stable indefinitely. All the others disintegrate
spontaneously with the release of energy by
processes broadly designated as radioactive
decay. Each “parent” radioactive isotope
eventually decays into one or at most a few
stable isotope “daughters” specific to that parent.
The radioactive parent tritium (3H, or hydrogen-
3), for example, always turns into the daughter
helium-3 (3He) by emitting an electron.