chemistry

1.  The best means of personal protection from radiation for emergency responders is the implementation of three basic principles: time, distance, and shielding. Using the Inverse Square Law of radiation, what Geiger counter reading would you get for a radioactive material when you are four feet from the source (assume an initial reading of 6300 R at a distance of 1 foot from the source)? __________ R.

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3,Potassium-42 is a radioisotope that nutritionists use to determine whether the body is effectively using potassium at the cellular level. The half-life of potassium-42 is 12.4 hours. Assuming that a patient’s cells assimilate all the potassium chloride tagged with potassium-42, approximately what percentage of the dose remains in 2.1 days? __________ .

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