If a mineral has a daughter to parent ratio of 3: 1 (three daughter atoms for every one parent atom), how many half lives have passed since the mineral formed

Which is a character of nuclear fusion but not nuclear fission

Write the empirical chemical formula of calcium with a mass percent of 38.8, phosphorus with a mass percent of 20.0, and oxygen with a mass percent of 41.3.

Silver tarnishes as silver metal reacts with hydrogen sulfide, h2s, in the air. in this reaction, dark silver sulfide, au2s, covers the surface of silver. when silver is polished, this coating of silver sulfide can be removed from the surface. this makes the silver shiny again. enter the coefficients that balance the tarnishing reaction equation. (type 1 for no coefficient.)