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View Policies Current Attempt in Progress The iron isotope with 33 neutrons is used in medical applications. It is a B emitter. A sample of iron containing 1.44 picograms (pico - 10-12) of this isotope registers 261 decays per second. Calculate the half-life of the iron isotope. eTextbook and Media Save for Later yr Attempts: 0 of 3 used Submit Answer
View Policies Current Attempt in Progress Polonium-210 has a half-life of 138.4 days. If a sample contains 8.9 mg of 210Po, how many milligrams will remain after 365 days? How many emissions per second will this residue emit? eTextbook and Media mg Save for Later x 10 decays/s Attempts: 0 of 3 used Submit Answer
Question 12 of 25 Part 1 < Calculate the energy per y ray. The speed of light is 2.998E8 ms. eTextbook and Media Hint A positron has the same mass as an electron (9.109E-31 kg). When a positron and an electron annihilate, both masses are converted entirely into the energy of a pair of y rays. Save for Later > Part 2 Calculate the energy per one mole of y rays. J/mol -/4 Attempts: 0 of 3 used E 111 Submit Answer www
Phosphorus-30, which has a half-life of 150 seconds, decays by positron emission. Part 1 How long will it take for 2 % of this nuclide to decay? eTextbook and Media Hint Save for Later Part 2 How long will it take for 99,5 % of this nuclide to decay! Attempts: 0 of 3 used Submit Answer
Question 14 of 25 View Policies Current Attempt in Progress Sodium-24, ₁2-15.0h, can be used to study the sodium balance in animals. If a saline solution containing 25 ug of 2*Na is injected into an animal, how long can the study continue before only 24 ug is left? eTextbook and Media. Save for Later Attempts: 0 of 3 used Submit Answer