What is the mass in grams of 4.5*10^20 molecules of aspirin (C9H8O4)

Correct relationship between molecular formula and empirical formula

Which scenario is most similar to the type of collision that gas particles have according to kinetic molecular theory

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.