Colligative Properties and Kinetics 9a. Radioactive Cud decays with a t/2 of 12.8 days. What is the value of k in sec1? A sample contains 28.0 mg of Cu4. How many decay events will be produced in one second on average? A chemist obtains a fresh sample of Cu and measures its radioactivity. She then determines that to do an experiment, the radioactivity cannot fall below 19.5%. How long does she have to complete the experiment?

One of the challenges of nuclear technology is safe long-term storage of by-products and waste. How many years must pass before a sample of plutonium –239 (t½ = 2.4 x 104 years) decays to only 0.10% of its original activity?     ___________ years

Technetium -99 (Tc-99) is the most commonly used radiotracer in medicine. It is used to detect damaged heart, lung, and liver tissue in patients. Radiotracers follow the same kinetic properties as radioactive nuclei . Technetium -99 has a half -life of 6 hours . If a patient is injected with a 0.575 M solution of Tc- 99, how many hours will it take for 74%of the technetium -99 to decay?

Enter your answer in the provided box. Tritium, ³H, is radioactive, decaying by electron emission with a half-life of 12.5 years. In ordinary water, the ratio of ¹H to ³H is 1.0 × 10¹7 to 1. How many disintegrations will be observed per minute in a 2.25-kg sample of water? disintegrations min

C) U.JIMI NaOH 4. Identify X in the reactions below a) 23°Pu + 15n → 254FM + X b) 238U (Y, 7e) 253ES Y =

QUESTION 2 CH3NH2 + HC1 CH3NH3+ + CI- and A conjugate acid-base pair in the reaction shown is HCI; Cl- CH3NH3+; Cl- HCI; H30+ CH3NH2; HCI CH3NH2; Cl- Click Save and Submit to save and submit. Click Save All Answers to save all answers. DELL Esc F1 F3 F4 F5 F6 # $ 1 2 3 tab Q W E R caps lock A C

Phosphorus-32 is a commonly used radioactive nuclide in biochemical research, particularly in studies of nucleic acids. The half-life of phosphorus-32 is 14.3 days. What mass of phosphorus-32 is left from an original sample of 175 mg of Na332PO4 after 47.2 days? Assume that the atomic mass of 32P is 32.0.

Carbon 14 decays to carbon12. The half-life of the C14 isotope is 5730 years. 3000 years after an animal dies, about  ______ of the carbon 14 will have been replaced with carbon12, while _____ will remain in a bone sample from the animals skeleton found by the archaeologists. "     about 75%, about 25%     about 7/8ths, about 1/8th     about 30%, about 70%     a little more than half, a little less than half

Chromium-51 is a radioisotope that is used to assess the lifetime of red blood cells The half-life of chromium-51 is 27.7 days. If you begin with 28.7 mg of this isotope, what mass remains after 55.1 days have passed?

Radon, one of the noble gases, is a decay product of uranium and is itself radioactive, with a half-life of 3.8 days3.8 days. As a heavy gas, radon can accumulate in low areas such as basements and crawl spaces. Consequently, radon is considered a significant source of air pollution and radiation exposure and, according to the EPA, is the second most frequent cause of lung cancer in the United States. Write the nuclear equation for the alpha decay of Rn‑222. nuclear equation: