About 12% of your body mass is carbon; some of this is radioactive 14C, a beta-emitter. Part A If you absorb 100% of the 49 keV energy of each 14C decay, what dose equivalent in Sv do you receive each year from the 14C in your body? Express your answer with the appropriate units. ΜΑ Dose equivalent = Value Units ?

Data from the appendices and the periodic table may be needed for these problems. Show that the activity of the 14C in 1.00 g of 12C found in living tissue is 0.250 Bq.

(a) A cancer patient is exposed to rays from a 5000Ci 60Co transillumination unit for 32.0 s. The rays are collimated in such a manner that only 1.00% of them strike the patient. Of those, 20.0% are absorbed in a tumor having a mass of 1.50 kg. What is the dose in rem to the tumor, it the average energy per decay is 1.25 MeV? None of the s from the decay reach the patient. (b) Is the dose consistent with stated therapeutic doses?

(a) Background radiation due to 226Ra averages only 0.01 mSv/y, but it can range upward depending on where a 226Ra in the 80.0kg body of a man who receives a dose of 2.50mSv/y from it, noting that each 226Ra decay emits a 4.80MeV particle. You may person lives. Find the mass of neglect dose due to daughters and assume a constant amount, evenly distributed due to balanced ingestion and handily elimination. (b) Is it surprising that such a small mass could cause a measurable radiation dose? Explain.

A beam of 168MeV nitrogen nuclei is used for cancer therapy. If this beam is directed onto a 0.200kg tumor and gives it a 2.00Sv dose, how many nitrogen nuclei were stopped? (Use an RBE of 20 for heavy ions.)

Data from the appendices and the periodic table may be needed for these problems. (a) Calculate the activity R in curies at 1.00 g of 226Ra. (b) Discuss why your answer is not exactly 1.00 Ci, given that the curie was originally supposed to be exactly the activity of a gram of radium.

In a 3109 yearold rock that originally contained some 238U, which has a halflife of 4.5109 years, we expect to find some 238U remaining in it. Why are 226Ra, 222Rn, and 210Po also found in such a rock, even though they have much shorter halflives (1600 years, 3.8 days, and 133 days, respectively)?

Large amounts of 65Zn are produced in copper exposed to accelerator beams. While machining contaminated copper, a physicist ingests 50.0 Ci of 65Zn. Each 65Zn decay emits an average ray energy of 0.550 MeV, 40.0% of which is absorbed in the scientist’s 75.0kg body. What dose in mSv is caused by this in one day?