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Radioactivity
Page 9
Questions (537)
About twenty radioisotopes with ultra-long half-lives, from 82 million years (244- Plutonium) to 6 million billion years
2 answers
asked by
Allie
521 views
The half life of radium is 3.82 days.In what time will the activity decay to 1/16 of its original value.
2 answers
asked by
Anju
532 views
The quantity Q of radioactive carbon remaining in a 200-gram wood sample at time t is given by the expression
Q(t)=200e^(−0.000
3 answers
asked by
Ann
523 views
1.The remains of an old campfire are unearthed and it is found that there is only 80% as much radioactive carbon-14 in the
4 answers
asked by
hannah
520 views
what fraction of an original sample of a radioactive isotope remains after three half-lives have passed?
1/8?
2 answers
asked by
jake
507 views
University students, studying the activity of a particular radioactive isotope which had a half-life of 12.0 hours. If the
2 answers
asked by
Anonymous
536 views
The quantity Q of radioactive carbon remaining in a 300 - gram wood sample at time t is given by the expression
Q(t) = 300 e^{-
3 answers
asked by
Irina
508 views
If a radioactive isotope has a half-life of 1 year, how much of the original sample will be left at the end of the 2nd year?
2 answers
asked by
Anonymous
508 views
The average human body has 1.4x10^2 g of total K within it. Calculate the activity in disintegration/year of the potassium-40 in
2 answers
asked by
Ro
515 views
A radioisotope has a half-life of 7.5 hours. How many half lives have occured after 67.5 hours?
a. 7 half-lives b. 8 half-lives
1 answer
asked anonymously
66 views
How many half-lives does it take a radioactive substance to decay until only one-eighth of the original substance remains? a
1 answer
asked by
cyan
90 views
If a 40 gram sample of radioactive isotope was present at 4pm, but a 5 gram sample remained at 4:30 pm, what is the half-life in
2 answers
asked by
Jason
508 views
A radioactive source of a single nuclide emits 2.4-MeV neutrons at the rate of 9200 neutrons per second. The number of atoms in
1 answer
asked by
jay
510 views
What are the various uses of radioactivity in healthcare? What are the future trends in healthcare with respect to the use of
2 answers
asked by
Anonymous
481 views
If 60% of a radioactive element remains radioactive after 200 million years, then what percent remains radioactive after
3 answers
asked by
aniyah
489 views
The radioactive nuclide 18F decays by first order kinetics with a half life of 1.83 hr.
How many hours will it take for 68.5% of
2 answers
asked by
Molly
489 views
the half-life of iodine-131 is 8 days. how much iodine-131 will be left after 8 days if you have an initial mass of 1g ?
3 answers
asked by
hamad
496 views
Suppose a patient is given 140mg of I−131, a beta emitter with a half-life of 8.0 days.
Assuming that none of the I−131 is
1 answer
asked by
Tim
473 views
If the amount of radioactive iodine-123 in a sample decreases from 0.8 g to 0.1 g in 36.2 hours, what is the half-life of
3 answers
asked by
Sara
478 views
A radioactive element x has half life of 30 days and will decay to become another new element Y..
a) calculate decay constant b)
1 answer
asked by
Aboi
477 views
Cobalt-60, which undergoes beta decay, has a half-life of 5.26 yr.
(a) How many beta particles are emitted in 47.0 s by a 2.39-mg
2 answers
asked by
sara
484 views
A uranium nucleus 238U may stay in one piece for billions of years, but sooner or later it decays into an a particle of mass
2 answers
asked by
Anonymous
484 views
Suppose 32000 radioactive nuclei are in a sample. About how many remain after two days if the half-life is 22 hrs? What is the
2 answers
asked by
Anonymous
483 views
Element Y has a half life of 50days. How much of a 100mg of its sample will remain after 5 month?
2 answers
asked by
Olushola
459 views
A radioactive isotope of Bismuth undergoes Beta Decay with a half-life of 22 days. How long (in days) will it take the Activity
2 answers
asked by
Ash
477 views
If a sample of the radioactive nuclide 139Cs has an activity of 0.0730 Ci, what is the instantaneous rate of decomposition of
1 answer
asked by
Alicea
474 views
How a radioactive element will decay over time?
2 answers
asked by
john
458 views
Julie has 250 grams of a radioactive substance. The substance decays every hour. How long will it take until she has 20 grams of
2 answers
asked by
Sozy
471 views
If the half life- period of a radioactive element is 1600.After how many years will if remains 25% of his quantity
1 answer
asked by
Prince
478 views
A certain Geiger counter is known to respond to only 1 of every 1000 radiation events from a sample. Calculate the activity of
1 answer
asked by
Trixie
472 views
Grade 11 Physics
1. A decay that involves a high-speed electron is a(n) ________________ decay. a) α Particle b) β Particle c)
1 answer
asked anonymously
28 views
How long will it take for the 100mg of cesium-137 to decay to 6.25mg(1/16 the original amount)?
5 answers
asked by
lolo
462 views
A particular radioactive element has a half life of 10.0 days. How much is left after 30.0 days if the sample started with 345g?
1 answer
asked by
Please help
454 views
a radioisotope, Iodine-131, has a half life of 8.1 days. explain what this means. draw a particle diagram for a sample 12
1 answer
asked by
mason
480 views
If it takes 45 days for 80.0 mg of a particular radioactive isotope to decay to 10.0 mg what is its half-life?
1 answer
asked by
Josh
454 views
Hi
Radioactive decay - A radioactive nuclide has a decay constant of - 10^-6 s-1 what is its half life ? I have come up with is
1 answer
asked by
Freddo
477 views
Cobalt-60 has a 30 year half-life. How much of an 80 gram sample would remain after 60 years?
1 answer
asked by
max
474 views
A 10g sample of radioactive substances is lift to decay for five half-lives. How much of the radioactive substance remains?
1 answer
asked by
mirian hernandez
476 views
the half-life of iodine-131 is 8 days. how much iodine-131 will be left After 35 grams sample after 32 days?
1 answer
asked by
Tony
454 views
5. Cesium-137 is a radioactive isotope. The following formula represents the remaining amount of a 300 gram sample of cesium-137
1 answer
asked by
seb
454 views
An isotope has a half-life of 56 days. It now has 10,000 DPM/ml. What is the activity in the diluted specimen?
Very confused, any
3 answers
asked by
Kyle
442 views
43Lb has a half life of 42 minutes. If you start with 100 grams, how many grams will you have after 84 minutes?
1 answer
asked by
Sabrina
427 views
How much time would it take for 12000 atoms of nitrogen-13 (half-life is 7.13 s) to decay to 750 atoms?
a)35.65 s b)28.52 s
1 answer
asked by
Andrea
441 views
A sample contains 3.5×1019 radioactive atoms with a half life of 10000 years. How many atoms are expected to decay in the first
1 answer
asked by
Maria
443 views
Radium has a half-life of 1620 years and decays into radon, which has a half-life of 3.82 days. A 10-gm source of radium is
1 answer
asked by
Nivia
450 views
if 5/6th of a radioactive sample decay in 70 years and 1/6th remain. how can you find the half life without knowing the decay
1 answer
asked by
ronny
436 views
How much a 2.00 g 239 Pu would have decayed after 1.6 x 10^4 years? The half-life for 239 Pu is 2.4 x 10^4 years.
amount
1 answer
asked by
James
451 views
A certain radioactive element has a half life of 1 h. If you start with a 1-g sample of the element at noon, how much is left at
3 answers
asked by
Jennifer
434 views
What is the half-life of an isotope that decays to 50% of its original activity in 55.6 hours?
1 answer
asked by
Anonymous
427 views
the amount of radioactive substance prsent at anytime is given by q(t)=Q0e-0.1
How will it take for the radioactive substance x
1 answer
asked by
robyn
440 views
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