In the nuclear industry, workers use a rule of thumb that the radioactivity from any sample will be relatively harmless after 10 half-lives. Calculate the fraction of a radioactive sample that remains after this time

Which of these properties, used alone, would be least useful in identifying most minerals? a. color b. luster c. streak d. density

Why must humans find substitutes for many minerals found on earth? (a) form at an extremely slow rate (b) controlled by other countries (c) too deep in the earth to collect

Asolution is made by dissolving 2.3 moles of sodium chloride (nacl) in 0.155 kilograms of water. if the molal boiling point constant for water (kb) is 0.51 °c/m, what would be the boiling point of this solution? show all the steps taken to solve this problem.