what is the half life of an isotope of after 30 days you have 31.25 g remaining from a 250 g beginning sample size

How many grams of co(g) are there in 74.5 ml of the gas at 0.933 atm and 30o c?

All of the following are part of the biosphere except

The content of manganese (mn) in steel was determined spectrophotometrically and with the use of the standard addition method. an unknown sample of mn from a digested steel sample gave an absorbance of 0.185 when analyzed spectrophotometrically. when 5.00 ml of solution containing 95.5 ppm mn was added to 50.0 ml of the unknown steel solution (digested sample), the absorbance was 0.248. calculate the concentration, in parts-per-million (ppm), of mn in the digested steel sample solution.