life of 1.27 × 109 yr. The age of a mineral sample that has a mass ratio of 40Ar to 40K of 0.330 is ________ yr. Group of answer choices 2.55 × 109 1.77 × 109 3.62 × 108 5.23 × 108 3.85 × 109

The table below shows the radioactive decay of a 600 g sample of Iodine-125. % of Parent Isotope Remaining Time Half- Fraction of Parent (days) Lives Isotope Remaining Mass (g) of Parent Mass (g) of Daughter Isotope Isotope 100% 1/1 600 60 1 50% 1/2 120 300 300 25% 1/4 150 450 180 3 12.5% 1/8 75 525 240 4 6.25% 1/16 37.5 562.5 300 3.125% 1/32 18.75 581.25 360 1.56% 1/64 9.4 590.6 15. What percent of iodine is left if 5 half-lives have passed? 16. What percent of iodine-125 has decayed if there are 37.5 grams of the original sample left? 17. What is the half-life of Iodine-125? 18. What mass of the Iodine-125 has decayed after 6 half-lives? 19. What fraction of the Iodine-125 remains after 300 days have passed? 20. How many half-lives would have to pass for there to be only 1.2 grams remaining? 21.How many grams of the daughter isotope are there after three half-lives?

||| Understanding radioactive half life sample A medical technician is working with the four samples of radionuclides listed in the table below. Initially, each sample contains 19.00 umol 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 1/4 of the initial amount. A B C D Explanation symbol 33 15 188 75 127 54 227 89 radionuclide P Re Xe Ac Check half-life 25. days 17. hours 36. days 22. years initial radioactivity (choose one) B (choose one) (choose one) O (choose one) e time for amount of radionuclide to decrease to 1/4 of initial amount X days hours days years S MacBook Pro 0/3 Kimberly V ( Ⓒ2023 McGraw Hill LLC. All Rights Reserved. Terms of Use | Privacy Center | Accessibility ?圖□ 圆图 olo Ar

All the disintegrations of a sample of an unknown nuclide weighing 4.6 x 10-2 g were counted. In the first half-life of the sample, the total number of disintegrations counted was 4.3 x 1020. What is the atomic weight of the unknown element?