How many moles are in 5.0 x 1025 atoms of iron

Smog is the term used to describe the combination of fog and smoke

If a sample of radioactive isotopes takes 600 minutes to decay from 400 grams to 50 grams, what is the half-life of the isotope?

)in the deacon process for the manufacture of chlorine, hcl and o2 react to form cl2 and h2o. sufficient air (21 mole% o2, 79% n2) is fed to provide 35% excess oxygen, and the fractional conversion of hcl is 85%. calculate the mole fractions of the product stream components.