After three half-lives, what fraction of a radioactive sample remains.

Sulfuric acid (a component of acid rain) reacts with limestone (calcium carbonate) to produce calcium sulfate and carbon dioxide. this damages buildings and statues made of limestone. which solution of sulfuric acid will damage these structures more quickly? a. 0.001% b. 0.005% c. 0.010% d. 0.015%

What is the percent by mass of oxygen in fe2o3

Will mark brainliest how many electrons can be held in the energy level n = 4?