If the hydrogen ion concentration is 1×10 to the -13M, what is the PO each of the solution? Please answer this is urgent!!!

According to each substances heat of fusion, which of the items below requires more heat to be added per gram of substance to go from solid to liquid? silver sulfur water lead

  the mississippians were considered to be  horticulturalists, which means they were

Harry lives in a city, and he has a lung condition known as asthma. on certain days, harry has to stay inside because pollutants in the air make it difficult for him to breathe. which of these pollution sources are nonpoint sources that might bother harry if he goes outside? choose the two that apply.