1) The Roentgen is a measure of the quantity of ions produced in dry air by passage of radiation.
QUESTION 1 The is a measure of the quantity of ions produced in dry air by...
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 48.2 minutes , what is the half-life of this substance? B) An unknown radioactive substance has a half-life of 3.20 hours . If 24.3 g of the substance is currently present, what mass A0 was present 8.00 hours ago? C) Americium-241 is used in some smoke detectors....
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 76.2 minutes , what is the half-life of this substance? b)An unknown radioactive substance has a half-life of 3.20 hours . If 14.6 g of the substance is currently present, what mass A0 was present 8.00 hours ago? c) Americium-241 is used in some smoke detectors. It...
231 A 60 mg sample of a radioactive isotope decays to 50 mg after 4.7 days. a) Determine the half-life. b) How long will it take for the amount of the isotope to decrease to 20 mg?
Assume that a hypothetical radioactive isotope has a half-life of 15 years. A 100.0-mCi sample of this radioactive isotope is deposited in a lead container. How long it will take until the activity of this sample is reduced to 1.00 mCi?
In the parts that follow, use the following abbreviations for time: Measure of time Units of time minutes min hours h days d years yr 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 93.0 minutes , what is the half-life of this substance? Express your answer with the appropriate units. t(1/2) = ______ b) An...
The radioactive isotope, Fr - 223, has a half-life of 22 minutes. How many minutes will it take for an original sample to decay to 12.5% of its original amount? Express your answer in minutes. Enter only the numeric value of the answer without the units.
V Question 5 3.03 pts Suppose a radioactive isotope has a half-life t% = 99.1 hr. How long will it take for a sample of the isotope to decay to 3.0% of its original activity? a. 218 hr b. 0.0354hr c. 348 yr d. 297 hr e. 501 hr O a Ob Ос Question 6 3.03 pts A radioactive isotope has a half-life, t% = 27.3 yr How long will it take for a 3.27 mCi sample of this isotope...
The activity of a sample of gas obtained from a basement containing radon-222 was found to be 8 pCi/L. This isotope has a half-life of 3.8 days. If no additional radon-222 entered the basement, how long would it take for the activity to decline to 1 pCi/L?
Part A: Tritium is a radioactive isotope of the element hydrogen. Tritium has a half-life of 12.5 years. How many years would it take until only 3.22% of a sample remain? Answer should be in years. Part B: Radioactive Carbon-11 has a half life of only 20.3 minutes and an atomic mass number of 11 u. Calculate the activity of 3.58 g of Carbon-11. Answer should be in Bq.
Question 18 0 out of 1 points A radioactive isotope decays with a half-life of 8.02 minutes. If a sample of the isotope initially contains 5.00 g, what mass remains after 6.01 minutes? Selected Answer. 3.13 g Answers 2.979 1.139 1.87 g 3.139