Answer Happy

2. Table NU.1 lists some sources of household background radiation, all of which emit gamma radiation by various processes. For example, uranium-238 emits an alpha particle as well as gamma radiation when it decays, as shown in Equation NU.1. 93 U+He +234 90 Th Write nuclear equations for the other sources of background gamma radiation from Table NU.1: (2pts) A Potassium-40, a beta emitter Normal BIU X2 X2 → fx 了留|_| TX (2pts) B Americium-241, an alpha emitter Normal . BIU X2 X E = fx IT IŤ TEK (2pts) C Radon-222, an alpha emitter Normal . BI U X2 X2 = IT BY TX (2pts) 3. Cobalt-60 decays to produce nickel-60. Write a nuclear equation to identify the particle released by this process. Normal BI U X₂ X² = fx ® 1 留 x=i TX
(1 pts) 4. Positron sources are used in PET scans (PET = positron emission tomography), which are an important part of medical imaging used in diagnosis. One isotope used in PET scans is carbon-11, which decays as shown here: ice+1B Choose... Recall that during beta emission, a neutron decays into a proton. Based on the decay equation for i C, what change must be happening within the nucleus during positron emission? (1pts) 5. A tiny percent of all naturally occurring carbon atoms on Earth are carbon-14. Trees (and all living things) incorporate C-14 into their bodies when alive, but this ceases at death, after which the amount of C-14 present gradually decreases due to nuclear decay. Wooden artifacts from long ago can be dated by the percent of carbon-14 remaining in them. A sample of a wooden object from an archaeological site contains only 12.5% of the level of carbon-14 expected for a live tree. How many half-lives have passed since that piece of wood was a living tree? Choose... (1pts) 6. Approximately how much time has passed since that piece of wood was a living tree? (See Table NU.3. in the lab manual) Choose...