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Radioactive Decay
Page 8
Questions (597)
When an unstable nuclide emits a gamma ray, there is no change in its . . .
a) atomic number b) atomic mass number c) nucleon
6 answers
asked anonymously
29 views
The half-life for a 100-gram sample of radioactive element X is 5 days. How much of element X remains after 10 days have passed?
1 answer
asked anonymously
49 views
In 10 years, 25% of a radioactive substance decays. What is its half-life?
A. 25 years B. 24 years C. 20 years D. 29 years
1 answer
asked by
Darwin12
1,129 views
A rock contains 200. µmol 238U (t1/2 = 4.5 109 yr) and 116 µmol 206Pb. Assuming that all the 206Pb comes from decay of the
5 answers
asked by
Martin
1,127 views
assume the substance has a half-life of 11 years and the initial amount is 126 grams.
How much remains at the end of 8 years?
2 answers
asked by
Jackie
1,116 views
suppose you have 100grams of radioactive plutonium-239 with a half-life of 24,000 years. how many grams of plutonium-239 will
5 answers
asked by
matt
1,125 views
An isotope has a half-life of 97 years. how much of a 19-gram sample is left after 150 years?
2 answers
asked by
Miles
1,091 views
The half-life of radon-222 is 3.82 days. If a sample of gas contains 4.38ug of radon-222, how much will remain in the sample
2 answers
asked by
Leyah
1,078 views
Carbon-14 has a half-life of 5730 years. How long will it take 17 grams of carbon-14 to be reduced to 10 grams? Round to the
3 answers
asked by
mer
1,078 views
If a 100.0 gram sample of a radioactive isotope goes through three half-lives, how much of the original radioactive isotope will
3 answers
asked by
OhSnap
1,088 views
A smoke detector contains 0.2 mg of Americium 241 (Am-241), a radioactive element that decays in t years according to the
2 answers
asked by
Anonymous
1,061 views
The half-life of carbon-14, which is used in dating archaeological finds, is 5730 yr. Assume that 100% of the carbon-14 is
4 answers
asked by
Hanna
1,001 views
Carbon-14 has a half-life of approximately 5,730 years. How many half-lives have occurred in a sample that contains 50 percent
3 answers
asked by
ticie burke
1,026 views
the bridge was built, the wood
contained 15 grams of carbon-14. How much carbon- 14 would it have contained when it was found by
2 answers
asked by
Tran
969 views
A sample has a activity of 0.0065 Bq per gram of carbon. (a) Find the age of the sample, assuming that the activity per gram of
2 answers
asked by
PLEASE AND THANK YOU
1,000 views
In which type of radioactive decay does the nucleus become more stable without changing its identity?
A. beta-minus decay B.
1 answer
asked anonymously
55 views
carbon 14 has a half life of 5715 years. If you start with a 5 gram sample of 14C, what mass is left after 15,000 years?
3 answers
asked by
Mima
1,003 views
Sam is comparing the half-life of two isotopes of uranium. The half-life of Uranium-238 is 4.5×109 years. The half-life of
1 answer
asked anonymously
49 views
Po-218 is an alpha emitter with a half-life of 3.0 minutes. If a sample contains 69 mg of Po-218, how many alpha emissions would
2 answers
asked by
lisa
976 views
The radioactive isotope, phosphorus-32, has a half-life of 14.26 days. How much phosphorus-32 will remain after 60 days?
Please
3 answers
asked by
Ken
981 views
The half-life of uranium-235 is 700,000,000 years. The half-life of uranium-238 is 4.463×10^11 years longer. What is the
1 answer
asked anonymously
35 views
When a 226/88 Ra nucleus decays by emitting an alpha particle, what is the atomic number of the resulting nucleus? What is the
1 answer
asked by
Chad
945 views
how many half-lives of radon-222 have passed in 11.46 days?
2 answers
asked by
Jerry
890 views
How many half-lives have passed if 87.5% of a substance has decomposed? How many if 99.999% has decomposed?
For 87.5%
1 answer
asked by
John
929 views
Cesium-137 has a half life of 30.0 years. If initially there are 8.0 kg of cesium-137 present in a sample, how many kg will
2 answers
asked by
brian
914 views
An artifact was found and tested for its carbon-14 content. If 88% of the original carbon-14 was still present, what is its
2 answers
asked by
Anonymous
934 views
during radioactive decay atoms of a radioactive element break down and change into other atoms of another element-all at once
a)
3 answers
asked by
victoria
914 views
It takes about 10^16 years for just half the samarium-149 in nature to decay by alpha-particle emission. Write the decay
2 answers
asked by
Phillip
953 views
A sample of
131 I was purified and then analyzed for iodine content. It was found that the sample was 99.8% pure. 25 hours later
3 answers
asked by
zac
912 views
A radio substance has a half-life of 10 years. What is its annual decay rate?
2 answers
asked by
Billy
891 views
What can scientists learn from the rate at which radioactive elements decay?
A. a rock's absolute age* B. the relative age of
4 answers
asked by
Anonymous
893 views
Radioactive decay of granite and other rocks in Earth's interior provides sufficient energy to keep the interior molten, to heat
1 answer
asked by
christy
871 views
Can anyone help me find the half-life of strontium-90? I also need an explanation on how to do it. Thanks!!
Radioactive Decay of
2 answers
asked by
Jane
863 views
3. What can scientists learn from the rate at which radioactive elements decay? (1 point)
2 answers
asked by
Nicole
858 views
carbon 14 has a hlf life of 5700 years. scientists use this fact to determine the age of things made up of organic material.
3 answers
asked by
Anonymous
851 views
A radioactive nucleus of uranium-235 (mU = 235 u) decays spontaneously to thorium-231
by emitting an alpha particle (nucleus of a
1 answer
asked by
anonymus
861 views
if the wood in the bowl contains only 1/16 of its original C-14, then its age is four half-lives of C-14.
2 answers
asked by
Anthony
829 views
Carbon-14 has a half-life of 5730 y. How much of a 144 g sample of a carbon-14 will remain after 1.719 (times) 10 4y?
1 answer
asked by
David
834 views
``If 18g of a radioactive substance are present initially and 5 yr later only 9 g remain, how much of the substance will be
2 answers
asked by
Ernie
846 views
K-42 has a half-life of 12.4 hours. If you begin with 250g of
K-42, determine how much you will have left after 4 half-lives. How
2 answers
asked by
Jazmin
818 views
1.
What is the change in atomic mass number when an atom emits an alpha particle? decreases by 2 *decreases by 4 increases by 2
10 answers
asked by
Anonymous
6,312 views
Suppose a laboratory has a 38 g sample of polonium-210. The half-life of polonium-210 is about 138 days. How many half-lives of
7 answers
asked by
Joshua
2,756 views
A radioactive sample contains 3.25 1018 atoms of a nuclide that decays at a rate of 3.4 1013 disintegrations per 26 min.
(a) What
6 answers
asked by
Trixie
1,308 views
19. A radioactive nucleus decays to yield a bismuth-211 nucleus and an alpha particle. What was the identity of the original
2 answers
asked by
Zak
1,065 views
Aluminum-30 has a half-life of 3.6 seconds.
a) What percentage of an initial sample will remain after 10 seconds? b) What
1 answer
asked anonymously
28 views
A piece of wood found in an ancient city has a carbon-14 to carbon-12 ratio that is one-eighth the carbon-14 to carbon-12 ratio
3 answers
asked by
John
808 views
Help plzzz
Besides the major types of radioactive decay, there are two others: positron emission and electron capture. •
2 answers
asked by
Help!!! Maddie
803 views
half life of tritium is 12.5 years. how much will remain after 100 years if you started wit 256 grams?
4 answers
asked by
Anonymous
781 views
Phosphorus-32 (P-32) has a half-life of 14.2 days. If 200 g of this substance are present initially, find the amount Q(t)
1 answer
asked by
vanessa
772 views
Suppose a laboratory has a 31 g sample of polonium-210. The half-life of polonium-210 is about 138 days. How many half-lives of
1 answer
asked by
Anonymous
760 views
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