3. ISOTOPES
Isotopes are atoms with the same atomic number
but different mass numbers.
Every element has naturally occurring isotopes.
For Example:
4. Two Categories of isotopes:
Unstable – isotopes that continuously and
spontaneously break down/decay in other lower
atomic weight isotopes
Stable – isotopes that do not naturally decay but
can exist in natural materials in differing
proportions
5.
6. Radioisotopes/radioactive
isotopes
Radioisotopes/radioactive isotopes of an
element can be defined as atoms that
contain an unstable nucleus and dissipate
excess energy by spontaneously emitting
radiation in the form of alpha, beta and
gamma rays.
How do radioisotopes occur?
a) Naturally- as in radium-226, Carbon-12
b) artificially altering the atoms by by
using a nuclear reactor or a cyclotron.
7. Most of the isotopes which occur naturally
are stable.
A few naturally occurring isotopes and all
of the manmade isotopes are unstable.
9. Uses of Isotopes
Stable and radioactive isotopes have many applications in
science and medicines. Some of these are as follows:
Radioactive Iodine-131 is used as a tracer in diagnosing
thyroid problem.
Na-24 is used o trace the flow of blood and detect
possible constrictions and obstructions in the circulatory
system.
Iodine-123 is used to image the brain.
Cobalt-60 is commonly used to irradiate cancer cells in
the hope of killing or shrinking the tumors
Carbon-14 is used to trace the path of carbon in
photosynthesis.
10. Radioactive isotopes are used to determine the molecular
structure. For example, sulphur-35 has been used in the
structure determination of thiosulphate.
Radioactive isotopes are also used to study the mechanism
of chemical reactions.
Radioactive isotopes are used to date rocks, soils,
archaeological objects, and mummies.
11. Dangers of Radioisotopes
Radioisotopes that find their way into the environment
may cause harmful effects as radioactive contamination.
They can also cause damage if they are excessively used
during treatment or in other ways exposed to living
beings, by radiation poisoning.
Potential health damage from exposure to radioisotopes
depends on a number of factors, and can damage the
functions of healthy tissue/organs.
Radiation exposure can produce effects ranging from
skin redness and hair loss, to radiation burns and acute
radiation syndrome. Prolonged exposure can lead to cells
being damaged and in turn lead to cancer. Signs of
cancerous cells might not show up until years, or even
decades, after exposure.
12.
13. What are isotopes ?
How many isotopes does hydrogen
have? Name them.
In what forms do radioactive isotopes
dissipate ?
Can you list any risk of using
radioisotopes.
What are unstable isotopes ?