The table of parent-daughter isotopes shows three different isotope pairs that are used in radioisotope dating. Examine the chart and answer the following questions. Isotope Daughter of Parent Dating Range Half-Life Effective Parent (y) uranium-235 lead-207 710 million>10 million 22. Lead-207 is called the daughter of uranium-235. What does this mean? potassium-40 argon-40 1.3 billion 10 000 to 3 billion carbon-14 nitrogen-14 5730 up to 50 000 23. How old is a rock sample that oontains uranium-235 and lead-207 in equal amounts? 24. The age of Earth was first established in 1953 when Claire C. Patterson of the Califormia Institute of Technology used a uranium-lead clock to analyze rock. In comparing amounts of uranium-235 with lead-207, he established that about 8 half-lives of uranium-207 had passed since the rock formed. Using this data, estimate the age of Earth.

Ruthenium-106 (106Ru) is used to treat melanoma in the eye. This isotope decays by β– emission with a half-life of 373.59 days. One source of the isotope is reprocessed nuclear reactor fuel. How many protons and neutrons does the 106Ru nucleus contain? Identify the missing daughter nucleus in the β– emission decay of 106Ru below. How many years after 106Ru is implanted in the eye does it take for its decay rate (or activity) to be reduced to 27.5% of the initial decay rate? Use 1 year = 365 days.

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…

Understanding radioactive half life A medical technician is working with the four samples of radionuclides listed in the table below. Initially, each sample contains 18.00 μmol of the radionuclide. First, order the samples by decreasing initial radioactivity. Then calculate how long it will take for the amount of radionuclide in each sample to decrease to 1/8 of the initial amount. radionuclide sample initial radioactivity symbol half-life time for amount of radionuclide to decrease to 1/8 of initial amount 149 A Tb 4.0 hours (choose one) hours 65 122 B I 4.0 minutes (choose one) ☐ minutes 53 192 C Ir 74.0 days (choose one) ☐ days 77 52 D Mn 6.0 days ✓ (choose one) ☐ days 25 1 (highest) 2 ☑ 3 4 (lowest)