If exactly 1.00 µg of 22°Ra was used to paint the glow-in-the-dark dial of a wristwatch made in 1914, how radioactive is the watch in 1971? Express your answer in becquerels (Bq). The half-life of 226Ra is 1.60 x 103 years. Bq Part 2 Express your answer from above in microcuries (µCi). uCi

If exactly 1.00 μg of 226Ra was used to paint the glow-in-the-dark dial of a wristwatch made in 1914, how radioactive is the watch in 2011? Express your answer in becquerels (Bq). The half-life of 226Ra is 1.60 ×× 103 years.

Some Radioactive Isotopes Useful in Medical Imaging Mode of Isotope Decay Half-life Use in Medical Imaging B*, y B+, y 20.3 m Brain scan to trace glucose metabolism Brain scan to trace glucose metabolism Detect eye tumors Diagnose albinism, image the spleen and gastrointestinal tract Bone marrow function, diagnose anemias Whole-body scan for tumors Pancreas scan Lung ventilation scan Scan for bone diseases, including cancer Brain, liver, kidney, bone scans; diagnosis of damaged heart muscle Diagnosis of thyroid malfunction Kidney scan Heart scan and exercise stress test Carbon-11 Fluorine-18 F P Cr Fe Ga 109 m 14.3 d Phosphorus-32 Chromium-51 Iron-59 Gallium-67 Selenium-75 Krypton-81m Strontium-81 Technetium-99m E.C., Y В, у E.C., y E.C., y 27.7 d 44.5 d 78.3 h 118 d BlKr Sr vTe 13.3 s 22.2 m 6.01 h Iodine-131 Mercury-197 Thallium-201 В, у E.C., Y E.C., y 8.04 d 64.1 h 20!TI 3.05 d (1) The radioactive isotope phosphorus-32 is used in medical imaging as indicated on the table above. How…

14. Using a mass spectrometer, a sample of an ancient wooden object was found to have a ratio of 14C to 12C equal to 3.3×10 −13 as compared to a current biological sample, which has a ratio of 14C to ¹2C of 1.2×10 −12 (Given: t, is 5730 years) What is the age of the object? 15. For the reaction, 2 A(g) + B₂(g) → 2 AB(g) The rate law is; rate = k[A][B₂]³ At 22.0 °C, k = 1234 M-³s-¹. What would be the rate of the reaction if the concentration of A is 0.100 M and concentration of B₂ is 0.125 M.

Some Radioactive Isotopes Useful in Medical Imaging Mode of Decay Isotope Half-life Use in Medical Imaging B+, y B+, y Carbon-11 Fluorine-18 Phosphorus-32 Chromium-51 Brain scan to trace glucose metabolism Brain scan to trace glucose metabolism Detect eye tumors Diagnose albinism, image the spleen and gastrointestinal tract 20.3 m EF 109 m 14.3 d 27.7 d 44.5 d Cr Fe SiGa E.C., Y В, у E.C., Y E.C., Y Iron-59 Bone marrow function, diagmose anemias 78.3 h 118 d Whole-body : scan for tumors Pancreas scan Lung ventilation scan Scan for bone diseases, including cancer Brain, liver, kidney, bone scans; diagnosis of damaged heart muscle Diagnosis of thyroid malfunction Kidney scan Heart scan and exercise stress test 118 d 13.3 s Strontium-81 22.2 m Technetium-99m 6.01 h 8.04 d Iodine-131 B, y 1Hg 201TI Mercury-197 Thallium-201 E.C., Y 64.1 h E.C., y 3.05 d The radioactive isotope strontium-81 is used in medical imaging as indicated on the table above. If 51.l milligrams of strontium-81 is…

Archeologists continue to debate the arrival of the first humans in the Western Hemisphere. Radiocarbon dating of charcoal from a cave in Chile was used to establish the earliest date of human habitation in South America as 8700 years ago. This procedure involves comparing the 14C present in a sample of charcoal to the 14C present in a living tree of the same age. What fraction of the 14C initially present remained in the charcoal after 8700 years? The half-life of 14C is 5730 years. (Write the answer as a number with a decimal.)

Be sure to answer all parts. A freshly isolated sample of 90Y was found to have an activity of 2.9 x 105 disintegrations per minute at 1:00 p.m. on December 3, 2006. At 2:15 p.m. on December 17, 2006, its activity was measured again and found to be 7.7 x 10° disintegrations per minute. Calculate the half-life of 90Y. Enter your answer in scientific notation. x 10 minutes

​Strontium-90 is a radioactive material that decays according to the function A(t)=A0e−0.0244t, where A0 is the initial amount present and A is the amount present at time t​ (in years). Assume that a scientist has a sample of 500 grams of​strontium-90.   ​(a) What is the decay rate of​ strontium-90? ​(b) How much​ strontium-90 is left after 40​years? ​(c) When will only 300 grams of​ strontium-90 be​ left? ​(d) What is the​ half-life of​ strontium-90?