The unstable isotope 40K is used for dating rock samples. Its half-life is 1.28×109y. How many...
The unstable isotope 40K is used for dating rock samples. Its half-life is 1.28×109y. How many decays occur per second in a sample containing 1.61×10−6 g of 40K? What is the activity of the sample in curies?
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The unstable isotope 40K is used for dating rock samples. Its
half-life is 1.28×109y. How many...
The technique known as potassium-argon dating is used to date old lava flows. The potassium isotope,...
The technique known as potassium-argon dating is used to date old lava flows. The potassium isotope, ^40K has a 1.28 billion year half-life and is naturally present at very low levels. ^40K decays by beta emission into ^40Ar. Argon is a gas, and there is no argon in flowing lava because the gas escapes. Once the lava solidifies, any argon produced in the decay of ^40K is trapped inside and cannot escape. A geologist brings you a piece of solidified...
The isotope 40K can decay to either 40Ca or 40Ar; assume both decays have a half-life...
The isotope 40K can decay to either 40Ca or 40Ar; assume both decays have a half-life of 1.26 X 109 y. The ratio of the Ca produced to the Ar produced is 8.54/1=8.54. A sample originally had only 40K. It now has equal amounts of 40K and 40Ar; that is the ratio of K to Ar is 1/1=1. How old is the sample? (Hint: work this like other radioactive-dating problems, except that this decay has two products).
The average banana contains 0.436 g of potassium, and 0.012% of naturally occurring potassium is 40K,...
The average banana contains 0.436 g of potassium, and 0.012% of naturally occurring potassium is 40K, which has a half-life of 1.248 × 10^9 years and an atomic mass of 39.964 u. What is the activity of a freshly picked bunch containing three bananas? The activity is the number of 40K decays that occur per unit time. Activity is commonly measured in units of Becquerel (Bq), which is defined as decays per second. Recall that the atomic mass unit u...
7. anium-238 is an alpha-emitter with a half-life of 4.522 x 10 years and an isotope...
7. anium-238 is an alpha-emitter with a half-life of 4.522 x 10 years and an isotope mass of 238.0508 g/mol. This isotope is useful for dating geological samples. A rock from the ocean floor contains 0.4203 g Uranium-238. What is the activity of this rock (from 238U) in counts per minute? Show all of your work. 8. Scientists exploring the new element Covidium (Cv) discover it has various isotopes. Calculate the binding energy per nucleon in units of kJ for...
The radioactive isotope carbon-14 is used for radiocarbon dating. The half-life of carbon-14 is years. A...
The radioactive isotope carbon-14 is used for radiocarbon
dating. The half-life of carbon-14 is years. A wooden artifact in a
museum has a count that is times that found in living organisms.
Estimate the age of the artifact.
The radioactive isotope carbon-14 1s used for radiocarbon dating. The half-life of carbon-14 is 5730 103 years. 14 A wooden artifact in a museum has a C count that is 3.13 x 10 times that found in living organisms Estimate the age...
ReviewI Constants The technique known as potassium-argon dating is used to date volcanic rock and ash, and thus establish dates for nearby fossils like this hominid skull.(Figure 1) The potassi...
ReviewI Constants The technique known as potassium-argon dating is used to date volcanic rock and ash, and thus establish dates for nearby fossils like this hominid skull.(Figure 1) The potassium isotope "0K has a 1.28-billion-year half-life and is naturally present at very low levels. Its most common decay mode is beta-minus decay into the stable isotope 40 Ca, but 10.9% of its decays are beta-plus which result in the creation of the stable isotope 40 Ar. The high temperatures in...
Problem 6. (10 pts) The isotope 60Co is commonly used as a source of g rays in high-level industr...
Problem 6. (10 pts) The isotope 60Co is commonly used as a source of g rays in high-level industrial irradiation cells. How many kg of 60Co are needed to achieve an activity of 106 curie = 3.7x1010 decays per second? After what time interval will the activity of such a cell have decreased to 10% of its initial value?
Problem 6. (10 pts) The isotope 60Co is commonly used as a source of g rays in high-level industrial irradiation cells....
Problem 30.44 Part A How many nuclei of U remain in a rock if the activity...
Problem 30.44 Part A How many nuclei of U remain in a rock if the activity registers 730 decays per second? The half-life is yr. Express your answer using two significant figures.
The half-life of a radioactive isotope is 220 d. How many days would it take for...
The half-life of a radioactive isotope is 220 d. How many days would it take for the decay rate of a sample of this isotope to fall to 0.47 of its initial rate?
Carbon-14 is a radioisotope that is used for dating biological organisms. The half-life of C-14 is...
Carbon-14 is a radioisotope that is used for dating biological organisms. The half-life of C-14 is 5730 years. When a one-gram sample of carbon from fresh peat is measured for radioactivity, 900 beta decays are recorded every hour. A one-gram sample of carbon is obtained from a peat deposit and is measured for radioactivity. If 113 beta decays are observed every hour, how many half-lives of C-14 have passed since the deposit was formed? A. 1/8 B.3 C.113 D.8 Approximately...
The technique known as potassium-argon dating is used to date old lava flows. The potassium isotope, ^40K has a 1.28 billion year half-life and is naturally present at very low levels. ^40K decays by beta emission into ^40Ar. Argon is a gas, and there is no argon in flowing lava because the gas escapes. Once the lava solidifies, any argon produced in the decay of ^40K is trapped inside and cannot escape. A geologist brings you a piece of solidified...
7. anium-238 is an alpha-emitter with a half-life of 4.522 x 10 years and an isotope mass of 238.0508 g/mol. This isotope is useful for dating geological samples. A rock from the ocean floor contains 0.4203 g Uranium-238. What is the activity of this rock (from 238U) in counts per minute? Show all of your work. 8. Scientists exploring the new element Covidium (Cv) discover it has various isotopes. Calculate the binding energy per nucleon in units of kJ for...
The radioactive isotope carbon-14 is used for radiocarbon
dating. The half-life of carbon-14 is years. A wooden artifact in a
museum has a count that is times that found in living organisms.
Estimate the age of the artifact.
The radioactive isotope carbon-14 1s used for radiocarbon dating. The half-life of carbon-14 is 5730 103 years. 14 A wooden artifact in a museum has a C count that is 3.13 x 10 times that found in living organisms Estimate the age...
ReviewI Constants The technique known as potassium-argon dating is used to date volcanic rock and ash, and thus establish dates for nearby fossils like this hominid skull.(Figure 1) The potassium isotope "0K has a 1.28-billion-year half-life and is naturally present at very low levels. Its most common decay mode is beta-minus decay into the stable isotope 40 Ca, but 10.9% of its decays are beta-plus which result in the creation of the stable isotope 40 Ar. The high temperatures in...
Problem 6. (10 pts) The isotope 60Co is commonly used as a source of g rays in high-level industrial irradiation cells. How many kg of 60Co are needed to achieve an activity of 106 curie = 3.7x1010 decays per second? After what time interval will the activity of such a cell have decreased to 10% of its initial value?
Problem 6. (10 pts) The isotope 60Co is commonly used as a source of g rays in high-level industrial irradiation cells....
Problem 30.44 Part A How many nuclei of U remain in a rock if the activity registers 730 decays per second? The half-life is yr. Express your answer using two significant figures.
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