An isotope with a half-life of 15.0 seconds was produced as a byproduct of a nuclear reaction experiment. How many half-lives pass after exactly 60.0 seconds have elapsed?
Enter only a number.

What is the molar mass of a gas that has density of 2.054 g/l

One way in which the useful metal copper is produced is by dissolving the mineral azurite, which contains copper(ii) carbonate, in concentrated sulfuric acid. the sulfuric acid reacts with the copper(ii) carbonate to produce a blue solution of copper(ii) sulfate. scrap iron is then added to this solution, and pure copper metal precipitates out because of the following chemical reaction: (s) (aq) (s) (aq) suppose an industrial quality-control chemist analyzes a sample from a copper processing plant in the following way. he adds powdered iron to a copper(ii) sulfate sample from the plant until no more copper will precipitate. he then washes, dries, and weighs the precipitate, and finds that it has a mass of .

How many moles of na2s2o3 are needed to react with 0.12mol of cl2? show work.