A1.0 g sample of hydrogen reacts completely with 19.0 g of fluorine to form a compound of hydrogen and fluorine. a. what is the percent by mass of each element in the compound? b. what mass of hydrogen would be present in a 50 g sample of this compound? c. justify your answer to b.

When a spring is compressed, the energy changes from kinetic to potential. which best describes what is causing this change?

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 are isotopes of the same element alike?