The document discusses isotopes, which are atoms of the same element that differ in the number of neutrons and consequently mass. Isotopes have the same chemical properties but slightly different physical properties. Various methods are presented for representing isotopes using atomic notation and mass notation. Examples of carbon and hydrogen isotopes are shown along with their subatomic particle makeup. Radioactive decay of isotopes is also discussed.
13. Various ways of identifying
Isotopes
• Using atomic notation,
Example: 12
6 C or simply 12 C
•Using the mass notation.
Example: Carbon-12 or C-12
(read “carbon twelve” or “C twelve”)
14. Some Isotopes of Carbon
mass
notation
atomic
notation
# of p+ # of e- # of no
C-11 11C 6 6
C-12 12C 6 6
C-13 13C 6 6
C-14 14C 6 6
16. The Isotopes of Hydrogen
mass
notation
atomic
notation
# of p+ # of e- # of no
Hydrogen-1 1H 1 1
Hydrogen-2 2H 1 1
Hydrogen-3 3H 1 1
17. p+ =
no =
e- =
p+ =
no =
e- =
p+ =
no =
e- =
Figure #1 Figure #2 Figure #3
18. Isotopes
atoms of a given element that
differ in the number of neutrons
…and consequently in mass.
19. Keep in mind:
It is not possible to determine how many
different isotopes exist by looking at the
periodic table.
It is not possible to determine the
frequency of various nuclides by looking
at the periodic table.
20. (parenthesis) on the
Periodic Table indicate the
most stable isotope
stable means “longest living”
Parenthesis also suggest the element of
interest is radioactive.
25. Stable vs. Unstable
• A stable isotope does NOT undergo
radioactive (or nuclear) decay.
• An unstable isotope undergoes
radioactive (or nuclear) decay.
Unstable isotopes are also known
as radioisotopes or radionucleides
26. Stable vs. Unstable
• Stable isotopes:
• They do not naturally decay but exist in
natural materials in differing
proportions.
• Unstable isotope
• Isotopes that continuously break down
into lower atomic weight isotopes.
27. Uses of Radioactive Isotopes
• Food irradiation
• Archaeological dating (carbon-
dating)
• Smoke detectors
• Radioactive tracers
30. Represent the following using ATOMIC NOTATION
17
Cl
Chlorine
37.65
8
O
Oxygen
17.999
92
U
Uranium
235.0289
6
C
Caarbon
14.011
9
F
Flourine
14.998
31. Represent the following using MASS NOTATION
27
Co
Cobalt
60.998
33
As
Arsenic
72.922
92
U
Uranium
235.0289
53
I
Iodine
131.404
11
Na
Sodium
24.989
32. The Isotopes
How many total subatomic particles are in the following:
Complete the table.
mass
notation
atomic
notation
# of p+ # of e- # of no
Lead-208 82
199Au
Bismuth-211 83
33.
34. The Isotopes
How many total subatomic particles are in the following:
Complete the table.
mass
notation
atomic
notation
# of p+ # of e- # of no
Lead-208 208Pb 82 82 126
Gold-199 199Au 79 79 120
Bismuth-211 211Bi 83 83 128
