| Sections | |||
|---|---|---|---|
| Radioactive Decay | 42 mins | 0 completed | Learn |
| Band of Stability | 22 mins | 0 completed | Learn |
| Magic Numbers | 10 mins | 0 completed | Learn |
| First Order Half Life | 19 mins | 0 completed | Learn |
| Additional Practice |
|---|
| Alpha Decay |
| Beta Decay |
| Gamma Emission |
| Electron Capture |
| Positron Emission |
| Nuclear Fission |
| Mass Defect |
| Nuclear Fusion |
| Nuclear Transmutation |
Solution: lodine-131 is a radioactive isotope. After 3.00 days, 77.2% of a sample of 131I remains. What is the half-life of 131I?
Problem
lodine-131 is a radioactive isotope. After 3.00 days, 77.2% of a sample of 131I remains. What is the half-life of 131I?
Practice Problems
The radioactive isotope 19O, prepared by neutron i...
The approximate date of an earthquake that occured...
222Ra is a naturally occurring radioisotope that c...
The specific activity of 14C in the biosphere is 0...
The half-life of nickel-63 is 85 years. How old is...
The half-life of iodine-131 is 8.04 days. Calculat...
A sample of a dish from an archaeological dig gave...
The decay constant for lithium-8 is 0.825 s-1. Wha...
Charcoal samples from Stonehenge in England were b...
Radon-220 undergoes alpha decay with a half-life o...
Radon-220 undergoes alpha decay with a half-life o...
Radon-220 undergoes alpha decay with a half-life o...
A sample initially contains 5.2 moles of a radioac...
Decay of a 10.0-g sample of strontium-90 (t1/2 ...
Cobalt-60, which undergoes beta decay, has a half-...
Cobalt-60, which undergoes beta decay, has a half-...
Some watch dials are coated with a phosphor, like ...
One of the nuclides in spent nuclear fuel is U-235...
A sample of F-18 has an initial decay rate of 1.6×...
A sample of Tl-201 has an initial decay rate of 5....
A layer of peat beneath the glacial sediments of t...
PET studies require fluorine-18, which is produced...
Iodine-131 is a convenient radioisotope to monitor...
The synthetic radioisotope technetium-99, which de...
A 26.10 g sample of water containing tritium, 13 ...
A 55.0 mg sample of sodium perchlorate contains r...
A sample of an alpha emitter having an activity of...
A sample of an alpha emitter having an activity of...
A 25.0-mL sample of 0.050 M barium nitrate solutio...
Approximately how many half-lives must pass for th...
Consider this graph representing the decay of a ra...
Each statement below refers to a comparison betwee...
Each statement below refers to a comparison betwee...
Each statement below refers to a comparison betwee...
Estimate the half-life of the isotope from the gra...
All the stable isotopes of boron, carbon, nitrogen...
A patient is given 0.055 µg of technetium-99m, a r...
At 8:00 A.M., a patient receives a 2.5 µg dose of ...
Cesium-137, a component of radioactive waste, has ...
An ancient skull has a carbon-14 decay rate of 0.8...
Cesium-137, which has a half-life of 30.2 yr, is a...
A rock from Australia contains 0.439 g of Pb-206 t...
It takes 4 h 39 min for a 2.00-mg sample of radium...
Bismuth-210 is beta emitter with a half-life of 5....
Bismuth-210 is beta emitter with a half-life of 5....
Polonium-218 is an alpha emitter with a half-life ...
Polonium-218 is an alpha emitter with a half-life ...
The half-life of 232Th is 1.4 x 1010 yr. Find the ...
The nuclide 38Cl decays by beta emission with a ha...
When 10BF3 is bombarded with neutrons, the boron-1...
A person is exposed for three days to identical am...
An artifact has a carbon-14 decay rate of 8.56 dis...
A radioactive sample contains 1.60 g of an isotope...
A radioisotope of technetium is useful in medical ...
A mammoth skeleton has a carbon-14 decay rate of 0...
If one-trillionth of the atoms of a radioactive is...
If 2.8×10−10% of the atoms of a radioactive isotop...
If 1.00×10−12 mol of 135Cs emits 1.39×105 β− parti...
A patient ingests 1.53 mg of 131I (Iodine-131), a ...
If 6.40×10−9 mol of 176W emits 1.07×1015 β+ partic...
The isotope 21283Bi has a half-life of 1.01 yr. Wh...
The half-life of radium-226 is 1.60×103 yr. How ma...
Some nuclear power plants use plutonium-239, which...
A rock contains 270 μmol of 238U (t1/2 = 4.5×109 y...
A fabric remnant from a burial site has a 14C/12C ...
The contents of a rock have a 206Pb to 238U mass r...
Plutonium-236 is an alpha emitter with a half-life...
A rock that contains 3.1×10−15 mol of 232Th (t1/2 ...
A researcher claims that an ancient scroll origina...
A volcanic eruption melts a large chunk of rock, a...
A researcher claims that an ancient scroll origina...
A 1.00 × 10 –6-g sample of nobelium, 254102 No, ha...
A 1.00 × 10 –6-g sample of nobelium, 254102 No, ha...
239Pu is a nuclear waste byproduct with a half-lif...
The isotope 208Tl undergoes β decay with a half-l...
The isotope 208Tl undergoes β decay with a half-l...
If 1.000 g of 22688Ra produces 0.0001 mL of the g...
The isotope 9038 Sr is one of the extremely hazar...
Uranium-238 undergoes a slow decay step (t1/2 = 4....
What is the age of mummified primate skin that con...
A sample of rock was found to contain 8.23 mg of r...
A sample of rock was found to contain 8.23 mg of r...
A sample of cobalt-60 (t1/2 = 5.27 yr), a powerful...
A laboratory investigation shows that a sample of ...
Isotope such as 26Al (half-life: 7.2 × 10 5 years...
An ancient sword has a blade from the early Roman ...
Americium-241 is widely used in smoke detectors. T...
Archeologists removed some charcoal from a Native ...
Krypton consists of several radioactive isotopes, ...
A layer of peat beneath the glacial sediments of t...
Radioactive copper-64 decays with a half-life of 1...
Radioactive copper-64 decays with a half-life of 1...
A chemist wishing to do an experiment requiring 4...
The curie (Ci) is a commonly used unit for measuri...
The curie (Ci) is a commonly used unit for measuri...
The first atomic explosion was detonated in the de...
What fraction of the 235U (t1/2 = 7.0×108 yr) crea...
Iodine-131 is used in the diagnosis and treatment ...
238U (t1/2 = 4.5×109 yr) begins a decay series tha...
Technetium-99 has been used as a radiographic agen...
Technetium-99m is a metastable nuclide used in num...
Phosphorus-32 is a commonly used radioactive nucli...
Technetium-99m is a metastable nuclide used in num...
The bromine-82 nucleus has a half-life of 1.0 X 10...
How many curies are produced by 1.0 mol of 40K (t1...
Fresh rainwater or surface water contains enough t...
The fraction of a radioactive isotope remaining at...
A living plant contains approximately the same fra...
The fraction of a radioactive isotope remaining at...
Assume a constant 14C/12C ratio of 13.6 counts per...
The fraction of a radioactive isotope remaining at...
A rock contains 0.688 mg 206Pb for every 1.000 mg...
The fraction of a radioactive isotope remaining at...
In the 1950s, radioactive material was spread over...
In the 1950s, radioactive material was spread over...
What volume of radon will be produced per hour at ...
90Kr (t1/2 = 32 s) is used to study respiration. H...
The accompanying graph illustrates the decay of 42...
How much time is required for a 6.30 mg sample of ...
The cloth shroud from around a mummy is found to h...
A wooden artifact from a Chinese temple has a 14C ...
Potassium-40 decays to argon-40 with a half-life o...
The half-life for the process 238 U → 206 Pb is ...
A meteor has a Pb-206:U-238 mass ratio of 0.850:1....
At a flea market, you’ve found a very interesting ...
Technetium-99m has a half-life of 6.01 hours. If a...
Define “third-life” in a similar way to “half-life...
A proposed system for storing nuclear wastes invol...
Iodine that enters the body is stored in the thyro...
During World War II, tritium ( 3H) was a component...
A laboratory rat is exposed to an alpha-radiation ...
Radium-226 (atomic mass = 226.025402 amu) decays t...
Iodine-131 has a half-life of 8.0 days. How many d...
Carbon from the remains of an extinct Australian m...
Rubidium-87 decays by β-particle production to str...
Tritium (3H; t1/2 = 12.26 yr) is continually forme...
An earthquake in the area of present-day San Franc...
According to current regulations, the maximum perm...
The half-life of 238U is 4.5 x 109 yr. A sample of...
Nuclear disarmament could be accomplished if weapo...
A 1.50-L gas sample at 726 mmHg and 25.0 ˚C contai...
A 226 mL sample of an aqueous solution contains 3....
The Sun radiates energy into space at the rate of ...
Uranium and radium are found in many rocky soils t...
The half-life of 235U, an alpha emitter, is 7.1 x ...
Tests on human subjects in Boston in 1965 and 1966...
Tests on human subjects in Boston in 1965 and 1966...
Suppose that an 90.0-gram laboratory animal ingest...
Suppose that an 90.0-gram laboratory animal ingest...
Suppose that an 90.0-gram laboratory animal ingest...
The hydride of an unstable nuclide of a Group IIA ...
Iron-59 is a beta emitter with a half-life of 44.5...
An igneous rock contains a Pb-206/U-238 mass ratio...
For the reaction 146 C ⟶ 147 N + ?, if 100.0 g of ...
The chart shows the mass of a decaying nuclide ver...
Plutonium-239 (t1/2 = 2.41×104 yr) represents a se...
Uranium-238 undergoes a slow decay step (t1/2 = 4....
Technetium-99 is often used for assessing heart, l...
Plutonium was detected in trace amounts in natural...
The rate constant for a certain radioactive nuclid...
A 5.4-μg sample of 226RaCl2 has a radioactivity of...
Radioactive copper-64 decays with a half-life of 1...
The accompanying graph illustrates the decay of 42...
The accompanying graph illustrates the decay of 42...
Radium-226, which undergoes alpha decay, has a hal...
Americium-241 is used in smoke detectors. It has a...
Given specimens uranium-232 (t 1/2 = 68.9 y) and u...
A scientist is studying a 2.234 g sample of thoriu...
A scientist is studying a 2.234 g sample of thoriu...
Given specimens neon-24 (t1/2 = 3.38 min) and bism...
A certain radioactive nuclide has a half-life of 3...
A certain radioactive nuclide has a half-life of 3...
Cobalt-60 is a strong gamma emitter that has a hal...
A wooden boat discovered just south of the Great P...
The half-life of a radioactive isotope is the amou...
The half-life for the radioactive decay of U-238 i...
The curve to the right shows the radioactive decay...
Analysis of a quartz crystal shows it to contain 2...If a fossil bone is found to contain an eighth as ...In how many days will a sample of polonium 210 wit...
Radium-226, which undergoes alpha decay, has a hal...
When a 2.50 g sample of cobalt-60 is stored for 10...
The half-lives of different medical radioisotopes ...
Suppose a person ingests equal amounts of two nucl...
A moon rock collected by a U.S. Apollo mission is ...
The half-life of Chromium-51 is 28 days. Starting ...Rate Constant for a First-Order Decomposition Reac...Be sure to answer all parts.A freshly isolated sam...Geologists can estimate the age of rocks by their ...An old asteroid is found. A rock from it yields 1....Enter your answer in the provided box.A rock sampl...The reaction below is first order in [H 2O2]: 2H2O...
The half-lives of different radioisotopes are give...One of the nuclides in spent nuclear fuel is U 235...
half-lives of different radioisotopes are given in...Be sure to answer all parts.The radioactive potass...Enter your answer in the provided box. What would ...Be sure to answer all parts.Given that the half-li...Some watch dials are coated with a phosphor, like ...The half-life of oxygen 15 is 124 s. If a sample o...Enter your answer in the provided box.What would b...A fossil is found to have a 14C level of 94.0% com...Fluorine-18 has a half life of 110 minutes, what p...Be sure to answer all parts.Archeologists can dete...The rate constant of a first-order process that ha...What is the half-life of an isotope that decays to...lodine-131 is a radioactive isotope. After 3.00 da...Be sure to answer all parts.The radioactive decay ...Given that the half-life of 238U is 4.51 x 109 ye...Gallium-67 is a radioactive isotope used in treatm...
A patient is given 0.050 mg of technetium-99 m (wh...Enter your answer in the provided box.Strontium-90...The radioactive element carbon-14 has a half-life ...If the amount of 51, used to label red blood cells...Calculate n (in 2008) for carbon-14 in charred pla...The half-lives of different radioisotopes are give...Be sure to answer all parts.Determine the age of r...After 45.0 min, 32.0% of a compound has decomposed...The half-life for the radioactive decay of C-14 is...A 50.0 mg sample of an unknown radioactive substan...The usefulness of radiocarbon dating is limited to...Calculate the amount of radioactive material remai...Be sure to answer all parts.A freshly isolated sam...You just discovered a radioactive element with an ...Sodium-24 has a half-life of 14.8 hours. How much ...The halt-lives of different medical radioisotopes ...A sample of F-18 has an initial decay rate of 1.2 ...Calculate the percent activity of the radioactive ...After 60.0 min, 42.0% of a compound has decomposed...What is the half-life of an isotope that decays to...A fossil is found to have a 14C level of 71.0% com...What is the half-life of an isotope that decays to...Consider comparing the two Phosphorous radionuclid...Provided in the table below are two isotopes and t...
The half-life of phosphorus-32 is 14.26 days. Calc...