If a sample of Fe2S3 contains 1.25x10ˣ15 iron atoms what is the mass in grams?

The reaction q+r2=r2q is found to be first order in r2 and

Why is nh3 classified as a polar molecule

Suppose the universe were completely empty except for one object-a solid sphere moving through space of 100 km/s. what sort of path would the object be moving in? explain your answer