Question
In: Physics
Rubidium-strontium dating. The rubidium isotope 8737Rb, a β emitter with a half-life of 4.75×1010yr, is used...
Rubidium-strontium dating. The rubidium isotope 8737Rb, a β emitter with a half-life of 4.75×1010yr, is used to determine the age of rocks and fossils. Rocks containing fossils of ancient animals contain a ratio of 8738Sr to 8737Rb of 0.0310.
Assuming that there was no 8738Sr3887Sr present when the rocks were formed, estimate the age of these fossils.
Solutions
Expert Solution
Radioactive decay of 
into 
is given below
+ 
Half life
is 4.75 
1010 years
Ratio of
to
found in the fossils of ancient animal = 0.031
Hence fraction of undecayed
atoms = 0.969
Hence from radioactive decay equation, we get
where T is half-life period of
ln(0.969) = [ -ln2
t ] / ( 4.75
1010 )
Hence age of rocks and fossil, t = - [ ln(0.969) / ln(2) ]
( 4.75
1010 ) year
t = 2.158
1010 year
genius_generous answered 2 years agoRelated Solutions
Rubidium-87 decays by β production to strontium-87 with a half life of 4.7 × 1010 years....
Rubidium-87 decays by β production to strontium-87 with a half
life of 4.7 × 1010 years. What is the age of a rock
sample that contains 105.9 µg 87Rb and 7.9 µg
87Sr ?
____ years old
Assume that no 87Sr was present when the rock was
formed.
The atomic masses are given in the table below:
Nuclide
Atomic Mass
87Rb
86.90919
87Sr
86.90888
Rubidium-87 decays by β production to strontium-87 with a half life of 4.7 × 1010 years....
Rubidium-87 decays by β production to strontium-87 with a half
life of 4.7 × 1010 years. What is the age of a rock
sample that contains 104.6 µg 87Rb and 7.1 µg
87Sr ?
Assume that no 87Sr was present when the rock was
formed.
The atomic masses are given below:
Nuclide
Atomic Mass
87Rb
86.90919
87Sr
86.90888
he isotope 81Thallium204 has a half-life of 3.78 years and can be used as a nanotechnology...
he isotope 81Thallium204 has a half-life of 3.78 years and can
be used as a nanotechnology MEMS (Micro Electric Mechanical System)
power source device. It decays through beta emission into 82Pb204
with a branching ratio of 97.1 percent with an average decay energy
of 0.764 MeV. It also decays through electron capture to 80Hg204
with a branching ratio of 2.9 percent with a decay energy of 0.347
MeV.
Calculate the energy release per decay event in
[MeV/disintegration]
Calculate its total...
The half-life of a radioactive isotope represents the average time it would take half of a...
The half-life of a radioactive isotope represents the average
time it would take half of a collection of this type of nucleus to
decay. For example, you start with a sample of 1000 Oxygen-15
(15O) nuclei, which has a half-life of 122 seconds.
After 122 seconds, half of the 15O nuclei will have
decayed into Nitrogen-15 (15N) nuclei. After another
122s, half of the remaining Oxygen nuclei will have also decayed,
and so on.
Suppose you start with 3.71×10315O nuclei...
The half-life of 235U, an alpha emitter, is 7.1×108 yr. Part A Calculate the number of...
The half-life of 235U, an alpha emitter, is 7.1×108 yr. Part A
Calculate the number of alpha particles emitted by 4.4 mg of this
nuclide in 2 minutes. Express your answer using two significant
figures.
Suppose a patient is given 140 mg of I−131, a beta emitter with a half-life of...
Suppose a patient is given 140 mg of I−131, a beta emitter with
a half-life of 8.0 days.Assuming that none of the I−131 is
eliminated from the person's body in the first 4.0 hours of
treatment, what is the exposure (in Ci) during those first four
hours? (please I need the correct answer with steps *no predictions
)
Polonium-218 is an alpha emitter with a half-life of 3.0 minutes. **)If a sample contains 55...
Polonium-218 is an alpha emitter with a half-life of 3.0
minutes.
**)If a sample contains 55 mg of Po−218 (atomic mass =
218.008965 amu), how many alpha emissions would occur in 27.0
minutes?
**)If the polonium were ingested by a person, to what dose of
radiation (in Ci) would the person be exposed? (I need correct
answer for this please)
Bismuth-210 is beta emitter with a half-life of 5.0 days. Part A If a sample contains...
Bismuth-210 is beta emitter with a half-life of 5.0 days. Part A
If a sample contains 1.2 g of Bi−210 (atomic mass = 209.984105
amu), how many beta emissions would occur in 14.0 days? Part B If a
person's body intercepts 5.8% of those emissions, to what dose of
radiation (in Ci) is the person exposed?
Strontium 38Sr90 has a half-life of 29.1 yr. It is chemically similar to calcium, enters the...
Strontium 38Sr90 has a half-life of 29.1 yr. It is chemically
similar to calcium, enters the body through the food chain, and
collects in the bones. Consequently, 38Sr90 is a particularly
serious health hazard. How long (in years) will it take for
99.9488% of the 38Sr90 released in a nuclear reactor accident to
disappear?
The half-life of a certain radioactive isotope is 3.24 years. If a sample consisting of 6.023x1023...
The half-life of a certain radioactive isotope is 3.24 years. If
a sample consisting of 6.023x1023 atoms were allowed to
decay, what percentage of the original number of atoms have decayed
after 2.0 years?
A) 50
B) 46
C) 32
D) 54
E) 60
ADVERTISEMENT
ADVERTISEMENT
Latest Questions
- 4) Cost per equivalent unit of direct materials and conversion (4 marks) The cost per equivalent...
- We usually write numbers in decimal form (or base 10), meaning numbers are composed using 10...
- Consider a saturated solution of the salt MX3, which M is a metal cation with a...
- Energyshot is a new energy drink that is about to be introduced into the global market....
- Problem 1: During the month, EKM Enterprise purchased $100,000 in raw material on account, used $150,000...
- An electron is accelerated inside a parallel plate capacitor. The electron leaves the negative plate with...
- There is a region with a constant magnetic field 6.31T . The magnetic field is directed...
ADVERTISEMENT