10. [-/3 Points] DETAILS COHENPCALC7 5.7.035. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Strontium-90, with a half-life of 28 years, is a radioactive waste product from nuclear fission reactors. One of the reasons great care is taken in the storage and disposal of this substance stems from the fact that strontium-90 is, in some chemical respects, similar to ordinary calcium. Thus strontium-90 in the biosphere, entering the food chain via plants or animals, would eventually be absorbed into our bones. (a) Compute the decay constant k for strontium-90. (Round your answer to four decimal places.) K = (b) Compute the time required if a given quantity of strontium-90 is to be stored until the radioactivity is reduced by a factor of 500. (Round your answer to the nearest whole number.) yr (c) Using half-lives, estimate the time required for a given sample to be reduced by a factor of 500. (Round your answer to the nearest whole number.) yr