2. Atomic number = # of protons in nucleus THE PERIODIC TABLE
# of nucleons = # of protons + # of neutrons
OF ELEMENTS
The number of neutrons can vary slightly for a given element (isotopes)
Atomic weight is equal to average number of nucleons in nucleus

3. Radioactivity: Birth of a new science
Milestones (important events) leading to establishment of nuclear
science as a subject
Discovery of X-Rays by W.C. Roentgen
X-
Discovery of Radioactivity by H. Becquerel
Discovery of Polonium and Radium by Marie and Pierre Curies
Discovery of electron by J.J. Thompson
Classification of radioactive emissions by E. Rutherford
Discovery of atomic nucleus by E. Rutherford
Enunciation of Rutherford-Soddy displacement law
Rutherford-
Discovery of neutron by J. Chadwick
Discovery of artificial radioactivity by Irene and J. Curies
Discovery of nuclear fission by O. Hahn and Strassmann

8. Atomic Structure
Inner
electron
shell
Proton
Nucleus
Neutron
Outer
electron
shell

9. Relative scale model of an atom and the
solar system
Do you perceive a gold ring to contain a larger fraction of solid matter
than the solar system?
On this scale, the nearest star would be a little over 10,000 miles
away

10. Nuclear notation
• Z = atomic number or proton number, is the
number of protons in the nucleus.
• N = neutron number, is the number of neutrons
in the nucleus.
• A = Z + N = mass number, is the number of
nucleons in the nucleus.
A
• In general, the notation is Z X N
• For example, 12 C6 has atomic mass 12.000
6

11. Radioactivity
• Questions
– How and why do nuclei decay?
– How do we use nuclear decay to tell time?
– What is the evidence for presence of now extinct
radionuclides in the early solar system?
– How much do you really need to know about
secular equilibrium and the U-series?
• Tools
– First-order ordinary differential equations

12. Enrico Fermi
(1901-1954)
-------------------------------
One fermi (f) = 10-15 m

13. r = 1.2 A1/3 (in f)
-------------------------
Helium: A = 4
r = 1.2 (4)1/3
= 1.9 f
-------------------------
Uranium: A = 238
r = 1.2 (238)1/3
= 7.4 f

14. Protons which would Beyond about one fermi
otherwise strongly repel the strong force declines
at close distances are extremely rapidly.
held in place by an
extremely strong, but As more protons are
extremely short range added to the nucleus,
force called the strong more neutrons are
force. Other names for needed to bind the
the strong force are protons together, but
strong nuclear force, or the larger the nucleus
nuclear force. becomes, the farther
apart are the protons
STRONG FORCE The strong force between and the less effective
two protons is about the is the strong force
Protons and neutrons in same as the strong force
the nucleus are between two neutrons, or
collectively referred to as a proton and a neutron.
nucleons.

15. Isotopes: Nuclides with same atomic number but different atomic
weight (or different neutron number)
All the nuclides belong to the same element
1 2 3 12 13 39 40 41
1H , 1H (D), 1H (T) 6C , 6C 19K , 19K , 19K
234, U235, U238
92U 92 92
Isobars: Nuclides with same atomic weight but different atomic
number (Nuclides belong to different elements)
18 Ar40, 19K40, 20Ca40
Isotones: Nuclides with the same number of neutrons.
12 13
5B , 6C both have 7 Neutrons
Mirror nuclei: Nuclides with neutron and proton number
interchanged
7 N15 and 8O15

17. In general, the mass defect is calculated by summing the mass of
protons, neutrons, and electrons in an atom, and subtracting the
atom’s actual atomic mass. The general formula is:
Md = Zmp + Nmn - Ma
Where Z is the atomic number, N is the number of neutrons in the
atom, and Ma is the actual measured mass of the atom. Placing Md
into Einstein's equation for relating mass and energy gives the
energy release from forming the atom from its constituent
particles:
E = Mdc2

19. Electric force is longer range
than the strong force.
Eventually separation becomes
too great for the strong force to
compensate for the repulsive
forces.
Nuclei spontaneously
disintegrate for proton numbers
larger than 83.
The release of light and or
particles which accompanies
the disintegration is called
radiation, first discovered by
Henri Becquerel in 1896.

20. Fundamental law of radioactive decay
• Each nucleus has a fixed probability of decaying per
unit time. Nothing affects this probability (e.g.,
temperature, pressure, bonding environment, etc.)
[exception: very high pressure promotes electron capture slightly]
• This is equivalent to saying that averaged over a large
enough number of atoms the number of decays per
unit time is proportional to the number of atoms
present.
dN
• Therefore in a closed system: = − λN (Equation 3.1)
dt
– N = number of parent nuclei at time t
– λ = decay constant = probability of decay per unit time (units:
s–1)
• To get time history of number of parent nuclei,
integrate 3.1: N (t ) = No e− λt (3.2)
– No = initial number of parent nuclei at time t = 0.

21. Definitions
• The mean life τ of a parent nuclide is given by the
number present divided by the removal rate (recall this
later when we talk about residence time):
N 1
τ= =
λN λ
– This is also the “e-folding” time of the decay:
− λτ −1 No
N (τ ) = No e = Noe =
e
• The half life t1/2 of a nucleus is the time after which
half the parent remains:
No − λt1/2 ln 2 .693
N (t1/ 2 ) = = Noe ⇒ λt1/ 2 = ln2 ⇒ t1/2 = ≈ (3.3)
2 λ λ
• The activity is decays per unit time, denoted by
parentheses: ( N ) = λN (3.4)

22. Decay of parent
λNo 0
ln(λN)–ln(λNo)
-1
Activity
λNo -2 slope = -1
2
λNo -3
e
-4
-5
0 t 1/2 τ 2τ 3τ 4τ 5τ 0 t 1/2 τ 2τ 3τ 4τ 5τ
time time
Some dating schemes only consider measurement of parent nuclei
because initial abundance is somehow known.
• 14C-14N: cosmic rays create a roughly constant atmospheric 14C
inventory, so that living matter has a roughly constant 14C/C ratio while it
exchanges CO2 with the environment through photosynthesis or diet.
After death this 14C decays with half life 5730 years. Hence even through
the daughter 14N is not retained or measured, age is calculated using:
14
1 ( C) / C
t= ln 14
[
λ14 ( C) / C ]o

23. Modes of decay
• A nucleus will be radioactive if by decaying it can
lower the overall mass, leading to larger (negative)
nuclear binding energy
– Yet another manifestation of the 2nd Law of thermodynamics
• Nuclei can spontaneously transform to lower mass
nuclei by one of five processes
– α-decay
– β-decay
– positron emission
– electron capture
– spontaneous fission
• Each process transforms a radioactive parent nucleus
into one or more daughter nuclei.

24. α-decay
Emission of an α-particle or 4He nucleus (2 neutrons, 2 protons)
α-decay The parent decreases its mass number
238
by 4, atomic number by 2.
92 U
# pr ot ons
91
Example: 238U -> 234Th + 4He
234
90 Th Mass-energy budget:
23
23
238U 238.0508 amu
8
144 145 146
23
23
# neutrons s
7
7
7
7
2
2
2
2
on 234Th –234.0436
3
3
3
36
le
2
uc 4He
35
35
n –4.00260
2
23
#
4
4
mass defect 0.0046 amu
AX → A−4Y + 4He = 0.0046 x 930.5 = 4.5 MeV
Z Z −2 2
X is called the parent nucleus and Y is called the daughter nucleus
This is the preferred decay mode of nuclei heavier than
209Bi with a proton/neutron ratio along the valley of
stability

25. β-decay
Emission of an electron (and an antineutrino) during
conversion of a neutron into a proton
The mass number does not change,
β-decay
the atomic number increases by 1.
# prot ons
87
38 Sr
Example: 87Rb -> 87Sr + e– + ν
37 87
Rb Mass-energy budget:
49 50 87Rb 86.909186 amu
8
88
# neutrons n s
eo
87
87
l 87Sr –86.908882
uc
86
86
86
86
n
# mass defect 0.0003 amu
= 0.0003 x 931 = 0.28 MeV
The emission of the electron is from the nucleus
The nucleus contains protons and neutrons
The process occurs when a neutron is
transformed into a proton and an electron
Energy must be conserved
This is the preferred decay mode of nuclei with excess
neutrons compared to the valley of stability

26. Beta Decay
• Symbolically A A −
Z X→ Y + e + ν
Z +1
A A
Z X→ Z−1Y + e + + ν
– ν is the symbol for the neutrino
– ν is the symbol for the antineutrino
• To summarize, in beta decay, the following
pairs of particles are emitted
– An electron and an antineutrino
– A positron and a neutrino

27. β+-decay and electron capture
Emission of a positron (and a neutrino) or capture of an
inner-shell electron during conversion of a proton into
a neutron
Electron Capture
The mass number does not change,
# prot ons
19 K 40
the atomic number decreases by 1.
40
18 Ar
21 22
4
41
s
Examples: 40K -> 40Ar + e+ + ν
# neutrons n
4
4
eo 50V+ e– -> 50Ti + ν + γ
0
0
cl
39
39
39
39
nu
#
In positron emission, most energy is
liberated by remote matter-antimatter
annihilation. In electron capture, a gamma
ray carries off the excess energy.
These are the preferred decay modes of nuclei with
excess protons compared to the valley of stability

28. Gamma Decay
• Gamma rays are given off when an excited nucleus
“falls” to a lower energy state
– Similar to the process of electron “jumps” to lower energy
states and giving off photons
• The excited nuclear states result from “jumps” made
by a proton or neutron
• The excited nuclear states may be the result of
violent collision or more likely of an alpha or beta
emission
• Example of a decay sequence 12 B→12 C * + e − + ν
5 6
– The first decay is a beta emission 12
6 C*→12 C + γ
6
– The second step is a gamma emission

29. Spontaneous Fission
Certain very heavy nuclei, particular those with even mass
numbers (e.g., 238U and 244Pu) can spontaneously fission.
Odd-mass heavy nuclei typically only fission in response to
neutron capture (e.g., 235U, 239Pu)
10
There is no fixed daughter product but rather a
235
statistical distribution of fission products with
U+n two peaks (most fissions are asymmetric).
1
Because of the curvature of the valley of
Fission Yield ( %)
stability, most fission daughters have excess
0.1
neutrons and tend to be radioactive (β-decays).
0.01
You can see why some of the isotopes people
worry about in nuclear fallout are 91Sr and 137Cs.
0.001 Recoil of daughter products leave fission tracks
of damage in crystals about 10 µm long, which
only heal above ~300°C and are therefore useful
0.0001
for low-temperature thermochronometry.
80 100 120 140 160 180
Atomic Mass (amu)

30. Natural Radioactivity
• Classification of nuclei
– Unstable nuclei found in nature
• Give rise to natural radioactivity
– Nuclei produced in the laboratory through nuclear
reactions
• Exhibit artificial radioactivity
• Three series of natural radioactivity exist
– Uranium-235 (4n + 3 series)
Uranium- ends at Pb-207
Pb-
– Uranium-238 (4n + 2 series)
Uranium- ends at Pb-206
Pb-
– Thorium-232 (4n series)
Thorium- ends at Pb-208
Pb-
4n + 1 series starting from Neptunium-237 is extinct
Neptunium-
ends at Bi-209
Bi-

32. Uses of Radioactivity
• Carbon Dating
– Beta decay of 14C is used to date organic samples
– The ratio of 14C to 12C is used
• Smoke detectors
– Ionization type smoke detectors use a radioactive
source to ionize the air in a chamber
– A voltage and current are maintained
– When smoke enters the chamber, the current is
decreased and the alarm sounds
• Radon pollution
– Radon is an inert, gaseous element associated
with the decay of radium
– It is present in uranium mines and in certain types
of rocks, bricks, etc that may be used in home
building
– May also come from the ground itself

33. Nuclear Reactions
• Structure of nuclei can be changed by
bombarding them with energetic particles
– The changes are called nuclear reactions
• As with nuclear decays, the atomic
numbers and mass numbers must balance
on both sides of the equation

34. Which of the following are possible
reactions?
(a) and (b). Reactions (a) and (b) both
conserve total charge and total mass number
as required. Reaction (c) violates
conservation of mass number with the sum
of the mass numbers being 240 before
reaction and being only 223 after reaction.

35. Determine the product of the reaction
7 Li + 4 He → X ? + n
3 2 Y
What is the Q value of the reaction?
In order to balance the reaction, the total amount of
Given: nucleons (sum of A-numbers) must be the same on
both sides. Same for the Z-number.
reaction
Number of nucleons (A): 7 + 4 = X + 1 ⇒ X = 10
Number of protons (Z): 3+ 2 = Y + 0 ⇒ Y = 5
Thus, it is B, i.e.
7
Find: 3 Li + 2 He → 10 B + 01n
4
5
Q=? The Q-value is then
( )
Q = ( ∆m ) c 2 = m7 Li + m 4 He − m10 B − mn c 2 = −2.79MeV

36. Processes of Nuclear Energy
• Fission
– A nucleus of large mass number splits into
two smaller nuclei
• Fusion
– Two light nuclei fuse to form a heavier
nucleus
• Large amounts of energy are released in
either case

37. Nuclear Fission
• A heavy nucleus splits into two smaller nuclei
• The total mass of the products is less than the original
mass of the heavy nucleus
• First observed in 1939 by Otto Hahn and Fritz
Strassman following basic studies by Fermi
• Lisa Meitner and Otto Frisch soon explained what had
happened
• Fission of 235U by a slow (low energy) neutron
1
0 n+ 235 U→236 U* → X + Y + neutrons
92 92
– 236U* is an intermediate, short-lived state
– X and Y are called fission fragments
• Many combinations of X and Y satisfy the requirements of
conservation of energy and charge

38. Sequence of Events in Fission
• The 235U nucleus captures a thermal (slow-moving) neutron
• This capture results in the formation of 236U*, and the excess energy
of this nucleus causes it to undergo violent oscillations
• The 236U* nucleus becomes highly elongated, and the force of
repulsion between the protons tends to increase the distortion
• The nucleus splits into two fragments, emitting several neutrons in
the process

39. Natural (radioactive) decay (fission)
Neutron-induced fission
• Many heavy elements (eg.
Uranium) decay (slowly) into
lighter elements (natural decay)
• However, this fission can also be
induced by an incoming neutron.
• Fission reaction release a lot of
energy.
• Fission often creates new
neutrons!!

40. Fission and
chain reaction
Fission releases neutrons …
… these neutrons cause new fission
reactions in surrounding Uranium …
… creating more neutrons …
… chain reaction

41. Energy in a Fission Process
• Binding energy for heavy nuclei is about 7.2 MeV per
nucleon
• Binding energy for intermediate nuclei is about 8.1 MeV
per nucleon
• Therefore, the fission fragments have less mass than the
nucleons in the original nuclei
• This decrease in mass per nucleon appears as released
energy in the fission event
• An estimate of the energy released
– Assume a total of 236 nucleons
– Releases about 0.9 MeV per nucleon
• 8.1 MeV – 7.2 MeV
– Total energy released is about 212 Mev
• This is very large compared to the amount of energy
released in chemical processes

42. Chain Reaction
• Neutrons are emitted when 235U undergoes fission
• These neutrons are then available to trigger fission in
other nuclei
• This process is called a chain reaction
–If uncontrolled, a
violent explosion can
occur
–The principle behind
the nuclear bomb, where
1 g of U can release
energy equal to about
20000 tons of TNT

44. Carbon dating is a variety of radioactive
dating which is applicable only to matter
which was once living and presumed to be in
equilibrium with the atmosphere, taking in
carbon dioxide from the air for photosynthesis.
Cosmic ray protons blast nuclei in the upper
atmosphere, producing neutrons which in turn
bombard nitrogen, the major constituent of
the atmosphere . This neutron bombardment
produces the radioactive isotope carbon-14.
carbon-
The radioactive carbon-14 combines with
carbon-
oxygen to form carbon dioxide and is
incorporated into the cycle of living things.
The carbon-14 forms at a rate which appears to be constant, so that by
carbon-
measuring the radioactive emissions from once-living matter and
once-
comparing its activity with the equilibrium level of living things, a
measurement of the time elapsed can be made.
made.

46. Radioactive Dating
Radioactive half-life of a given radioisotope is not affected
half-
by temperature, physical or chemical state, or any other
influence of the environment outside the nucleus.
nucleus.
Radioactive samples continue to decay at a predictable rate.
rate.
This makes several types of radioactive dating feasible.
feasible.
There are two main uncertainties in the dating process:
process:
1. What was the amount of the daughter element when
the rocks were formed?
2. Have any of the parent or daughter atoms been added
or removed during the process?

47. Balancing Nuclear Decay Equations
238 --------> 90Th234 + 2He4
92U Proton and nucleon counts
----------------------------------------- must
Subscripts are "proton be the same:
numbers" 92 = 90 + 2
Superscripts are "nucleon 238 = 234 + 4
numbers"
Distribution of Energy in Alpha Emission ∆m = 0.0046 u
E = 0.0046 x 931
= 4.3 MeV
-----------------------
Which particle
has the greater
kinetic energy?

48. Energy Distribution in Radioactive Decay
Conservation of
momentum:
Mv = mV (2)
Rearranging, we get
Ratio of kinetic energies: V/v = M/m (3)
KEm / KEM: (1/2 mV2) / (1/2 Mv2) Substitute (3) into (1):
= (m/M)(V2/v2) Ratio = (m/M)(M/m)2 (4)
= M/m
= (m/M)(V/v)2 (1) Smaller mass gets more
energy

49. Smoke Detector
Alpha particles emitted from
source ionize the air and
provide the charge necessary
to conduct current through
the air.
Charges stick to the heavy
smoke particles and the
current drops, causing the
alarm to buzz.

50. Wavelength of a Gamma Ray
What is the wavelength of a 1 MeV gamma ray?
Using the 1234 rule:
λ = 1234 eV-nm / E
= 1234 eV-nm / 1 x 106 eV
= 1.23 x 10-6 nm
= 1.23 x 10-15 m
= 1.23 fermi
This gamma radiation is extraordinarily harmful
to humans and other living things since its
wavelength is comparable to the diameter of
a nucleon; transmutations are likely when
such radiation reaches nuclei.

51. Measuring the Age of Organic Matter
A German tourist in
the Italian Alps
discovered the
remains of the
"Iceman" in the ice
of a glacier in 1991

52. Calculating the Iceman's Age
The current activity per gram of
carbon is 0.23 Bq per gram.
Iceman's carbon showed
0.121, or about half what it
would be if the Iceman were
alive.
Since the half-life of carbon-14
is about 5700 years, the
Iceman's remains are about
5700 years old.

53. The Shroud of Turin
Since the1354 AD, a
yellowing piece of linen
14-ft long has been
stored in Turin, Italy.
It bears the image of a
person who seems to
be wearing a crown of
thorns.
Could the Shroud of
Turin have been the
burial cloth of a person
who died two thousand
years ago?

54. Dating of the Shroud of Turin
At the time of the public exhibition of the
shroud in 1354, a bishop declared it to
be fraud. Most religious bodies take a
neutral stance on the shroud's
authenticity.
In 1988, three laboratories were given
four pieces of fabric; three were control
pieces similar in appearance, and one
was a piece from the shroud. The
labs all agreed that the shroud was 608-
728 years old, which means that it
came into existence sometime
between1260 and 1380 AD, a time
span which includes the year the
shroud was first shown to the public.

56. In 1934, Irene and Frederic Joliot-Curie discover the
artificial radioactivity, making a great step toward the use
and the control of radioactivity. For this discovery, they
received the Nobel price of chemistry in 1935.
They were the first to show that mankind could build under
control some news radioactive nuclei. By shooting an
aluminium sheet with alpha particles (helium nuclei), they
were able to make radioactive phosphorus, a new isotope of
the stable phosphorus that was never observed in nature.
They demonstrated it by chemically isolating the phosphorus
produced before it becomes silicium by its radioactivity. The
creation an unnatural radioactive element is what we call the
creation of artificial radioactivity.

57. Positrons
In 1930 Paul Dirac calculated the existence of electrons with positive charges. These "anti-electrons" would be
expected to have the same mass as the electron, but opposite electric charge. In 1932 Carl Anderson was examining
tracks produced by cosmic rays in a cloud chamber. One particle made a track like an electron, but the curvature of
its path in the magnetic field showed that it was positively charged. He named this positive electron a positron. We
know that the particle Anderson detected was the anti-electron predicted by Dirac. An electron and positron
annihilate one another producing two gamma rays (β- + β+® γ + γ).
Irene Curie-Joliot (1897-1956), the daughter of Marie & Pierre, and her husband Frédéric Joliot prepared
phosphorus-30 by bombarding aluminum with alpha particles..
Phosphorus-30 does not occur in nature and is radioactive. This was the first artificial radioactive substance ever
prepared. Aside from the three natural types of radioactivity (α,β,γ), artificially made nuclei can undergo:
Both positron emission and electron capture tend to occur for radioactive isotopes that need to convert a proton into
a neutron. The Curie-Joliots were awarded the Nobel Prize in Chemistry in 1935 for discovering artificial
radioactivity.

58. Chemical Reaction Nuclear reaction
Atoms are rearranged by Elements (or isotopes of
the breaking and formation the same elements) are
of chemical bonds converted from one to
another
Only electrons in atomic Protons, neutrons,
orbitals are involved in the electrons and other
breaking and forming of elementary particles may
bonds be involved
Absorption or release of Absorption or release of
small amounts of energy tremendous amounts of
energy
Rates of reactions are Rates of reactions are NOT
affected by temperature, affected by temperature,
pressure, concentration pressure, concentration
and catalysts and catalysts

62. Producing Radioactive Isotopes:
TRANSMUTATION is the process of changing one element
into another.
A stable atom can be bombarded with fast-moving a particles,
protons, or neutrons.
A radioactive isotope is called a RADIOISOTOPE.

63. Half-Life:
The HALF-LIFE of a radioisotope is the amount of time it
takes for half of the sample to decay.
A DECAY CURVE is a graph of the decay of a radioisotope
(amount vs. time).
Some radioisotopes have long half-lives. For other
radioisotopes, the half-life can be short.

64. Radioactivity
Penetrating power of different forms of radiation:
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66. Chemical reactions
CH4 + 2O2 CO2 + 2H2O + some energy
One molecule or element reacts with another one.
Get a rearrangement (different combination) of elements.
No new elements are created (C, H, O before and C, H, O after)

67. – a nuclear reaction
As an example, when uranium 238 emits
an alpha particle, it loses 2 protons and
2 neutrons.
238 234 4
92 U −− > 90 Th + He 2
– Nuclear reactions must balance just like
any other chemical reaction, but we must
also be aware of balancing protons and
neutrons

68. Nuclear Reactions
Nuclear reactions occur when a nucleus is struck by a
particle or other nucleus.
n+ 14 N → 1 4C + p
7 6
4H e+ 14 N → 1 7O 1
+ 1H
2 7 8
•The second reaction was observed by Rutherford and is the
first nuclear reaction observed.
•It should be noted that in the first reaction, the neutron can
enter the nucleus with very little energy but the 4He is repelled
by the nucleus and thus has to overcome the Coulomb barrier
in order to come close enough to cause a nuclear reaction.

69. Parameter Chemical Reaction Nuclear Reaction
Reaction H + H → H2 H + H → 2H (D)
Mechanism Interaction of Interaction of nuclei
electrons
Species Do not change New species form
Energy ∆H = 104.2 kCal/mol Q = 33.47 x 106
change 1.73 x 10-22 kCal.atom kCal/mol
(4.5 eV/atom) 5.56 x 10-17 kCal/atom
(1.452 MeV/atom)
Conservatio Maintained Maintained
n of mass
and energy

73. Radioactivity in Nature
Our world is radioactive and has been since it was created
Over 60 radionuclides (radioactive isotopes) can be found in nature.
Radionuclides are found in air, water, food and soil
Radionuclides are even found in our body
Everyday we ingest and inhale radionuclides
In addition to radionuclides found in nature
We have
Cosmogenic radionuclides: formed as a result of cosmic ray interactions
Man-made radionuclides
Number of radionuclides > 2000
Number of elements: 111

74. Natural Radioactivity in soil
How much natural radioactivity is found in a volume of soil that is 2.6 sq KM, 30
cm deep (total volume = 7.894 x 105 m3)
Every day, we ingest/inhale nuclides in our air we breath, in the food we eat
and the water we drink. Radioactivity is common in the rocks and soil that
makes up our planet, in the water and oceans, and even in our building
materials and homes. It is just everywhere. There is no where on Earth that you
can get away from Natural Radioactivity.
Radioactive elements are often called radioactive isotopes or radionuclides.
There are over 1,500 different radioactive nuclides

75. Natural Radioactivity in Food
Food 40K (pCi/kg) 226Ra (pCi/kg)
Banana 3,520 1
Carrot 3,400 0.6 - 2
White potatoes 3,400 1 – 2.5
Beer 390 ----
Red meat 3,000 0.5
Drinking water ----- 0 – 0.17
Handbook of radiation measurement and protection

76. Radionuclides in building materials
Material Uranium (µg/g)
(µg/g) Thorium (µg/g)
(µg/g) Potassium (µg/g)
(µg/g)
Granite 4.7 2 4
Sandstone 0.45 1.7 1.4
Cement 3.4 5.1 0.8
Limestone 2.3 2.1 0.3
concrete
Sandstone 0.8 2.1 1.3
concrete
Dry 1 3 0.3
wallboard
Byproduct 13.7 16.1 0.02
gypsum
Natural 1.1 1.8 0.5
gypsum
Wood - - 11.3
Clay brick 8.2 10.8 2.3

77. Some radionuclides in human body
Nuclide Total mass Total Daily
of nuclide activity intake
in the body
Uranium 90 µg 1.1 Bq 1.9 µg
Thorium 30 µg 0.11 Bq 3 µg
Potassium- 17 mg 4.4 kBq 0.39 mg
40
Radium 31 pg 1.1 Bq 2.3 pg
Carbon-14 95 µg 15 kBq 1.8 µg
Tritium 0.06 pg 23 Bq 0.003 pg