Mercury 197 has a decay rate of 1.066% per hour. given the exponential model representing the amount of mercury 197 remaining after t hours, find how long it will take 387 grams of the mercury 197 to decay to 38 grams. round your result to the nearest thousandth hour.

Which of these would be caused by a chemical change? a) the formation of lava. b) sedimantary rock layering over time. c) metamorphic rock forming from igneous. d) metamorphic rock eroding to form sedimentary rock.

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 of the following is true about the speed of light? it depends on the wavelength.