Question
In: Physics
The activity of a sample of radioactive material was measured over 12 h. The following net...
The activity of a sample of radioactive material was measured over 12 h. The following net count rates were obtained at the times indicated:
| Time (h) | Counting Rate (counts/min) |
| 1 | 3100 |
| 2 | 2450 |
| 4 | 1480 |
| 6 | 910 |
| 8 | 545 |
| 10 | 330 |
| 12 | 200 |
1a + b) Wanted you to find the disintegration constant and the half-life. I've found those correctly. The disintegration constant is .24974 h^-1, and the half-life is 2.77 hours. (you had to take ln() and find the slope, etc.)
1c) Was to find the counting rate at t = 0. Which is 4*10^3 counts/min.
However, I am stuck on 1d... How do I acheive an answer of 9.59*10^6?
1d) Assuming the efficiency of the counting instrument to be 10%, calculate the number of radioactive atoms in the sample at t = 0???
Solutions
genius_generous answered 2 years agoRelated Solutions
The activity of a sample of radioactive material was measured over 12 h. The following net...
The activity of a sample of radioactive material was measured
over 12 h. The following net count rates were obtained at the times
indicated:
Time (h)
Counting Rate (counts/min)
1
3100
2
2450
4
1480
6
910
8
545
10
330
12
200
1a) Plot the activity curve on semilog paper.
1b) Determine the disintegration constant and the half-life of
the radioactive nuclei in the sample.
The quantity of a radioactive material is often measured by its activity (measured in curies or...
The quantity of a radioactive material is often measured by its
activity (measured in curies or millicuries) rather than by its
mass. In a brain scan procedure, a 84.0−kg patient is injected with
19.0 mCi of 99mTc, which decays by emitting γ−ray photons with a
half-life of 6.01 h. Given that the RBE of these photons is 0.98
and exactly two-thirds of the photons are absorbed by the body,
calculate the rem dose received by the patient. Assume all the...
When studying radioactive material, a nuclear engineer found that over 365 days, 1,000,000 radioactive atoms decayed...
When studying radioactive material, a nuclear engineer found
that over 365 days, 1,000,000 radioactive atoms decayed to 973,133
radioactive atoms, so 26,867 atoms decayed during 365 days.
a. Find the mean number of radioactive atoms that decayed in a
day.
b. Find the probability that on a given day, 50 radioactive
atoms decayed.
Thanks in advance!
The activity of a radioactive sample is the number of decays per minute that occur in...
The activity of a radioactive sample is the number of decays per
minute that occur in the sample. We measured this by detecting the
radiation entering the Geiger tube window. Explain why our readings
were actually only a small fraction of the actual activity. Also,
why did that not seem to matter in the determination of
Barium-137m’s half-life? Refer to either your A vs. t or your ln A
vs. t graph in your explanation.
You are using a Geiger counter to measure the activity of a radioactive substance over the...
You are using a Geiger counter to measure the activity of a
radioactive substance over the course of several minutes. If the
reading of 400. counts has diminished to 100. counts after 63.7
minutes , what is the half-life of this substance?
If a spill of radioactive material occurred over an aquifer, estimate the length of time required...
If a spill of radioactive material occurred over an aquifer,
estimate the length of time required for the material to reach a
river 2 mi away if the aquifer is
a) Gravel
b) Clay
c) Sandstone
d) Granite
Groundwater elevation at the spill site is 100 ft above the
water surface in the river.
Exposure over a number of weeks to 20 MeV alpha particles will make a material radioactive....
Exposure over a number of weeks to 20 MeV alpha particles will
make a material radioactive.
True or False?
Part A:You are using a Geiger counter to measure the activity of a radioactive substance over...
Part A:You are using a Geiger counter to measure the activity of
a radioactive substance over the course of several minutes. If the
reading of 400. counts has diminished to 100. counts after 61.7
minutes , what is the half-life of this substance?
Part B; An unknown radioactive substance has a half-life of 3.20
hours . If 27.1 g of the substance is currently present, what mass
A0 was present 8.00 hours ago?
Part C:Americium-241 is used in some smoke...
The activity of a radioactive sample is the number nuclear disintegrations per second, which is equal...
The activity of a radioactive sample is the number nuclear
disintegrations per second, which is equal to the first-order rate
constant times the number of radioactive nuclei present. The
fundamental unit of radioactivity is the curie (Ci), where 1 Ci
corresponds to exactly 3.70 × 1010 disintegrations per second. This
decay rate is equivalent to that of 1 g of radium−226. The molar
mass of Ra−226 is 226.03 g/mol.
a.Calculate the rate constant for the radium
decay.
b.Calculate the half-life...
1) If a sample of the radioactive nucleide ^139Cs has an activity of 2.93 Ci, what...
1) If a sample of the radioactive nucleide ^139Cs has an
activity of 2.93 Ci, what is the instantaneous rate of
decomposition of ^139Cs in terms of grams per second? The mass of
^139Cs is 138.9134amu. (1 Ci = 3.700*10^10 disintegrations/s, 1 amu
= 1.66054*10^-24 g)
A. 2.93*10^-2 g/s
B. 6.76*10^-24 g/s
C. 8.53*10^-12 g/s
D. 1.83*10^-34 g/s
E. 2.5*10^-11 g/s
2) the half-life of the radioactive nucleide ^79As is 9.0min.
what is the activity of a 9.8g sample of...
ADVERTISEMENT
ADVERTISEMENT
Latest Questions
- Explain an example in which a variable has two different addresses at different places in a...
- Hadley, a thirty-five-year-old physician, has worked at Princeton Plainsboro Hospital for six years. She recently received...
- QUESTION 1. For each of the following, state whether the occurrence of the variable x occurs...
- According to Mike Taft of RVK, the “Markets Group” is an important unit of the Federal...
- Describe the process of STP from implementation to convergence.
- Convert the following numbers as indicated. Use as few digits in the results as necessary or...
- Java program to implement the merge sort your own and test it to sort a list...
ADVERTISEMENT