a rock that originally had a mass of 1.00g of uranium_238 now only has .125g left. how old is the rock if the half life of uranium_238 is 4.5 billion years?

Calculate the mass of silver needed to react with chlorine to produce 126g if silver chloride?

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.

Which property of water causes water drops to bead on a freshly waxed car?