Samples of groundwater were collected and analyzed using absorption spectrophotometry. The samples contained 100 ppm of Calcium and 80 ppm of Magnesium to give the total hardness of calcium carbonate. Express the total hardness of CaCO3 in parts per million.

there is none because earth is stationary and flat.

he uptake of drugs from the intestine is often strongly influenced by diffusion. for example, consider a water-insoluble steroid for treating inflammation that is solubilized in aggregates of detergent molecules, called micelles. these micelles, aggregates of 80 soap molecules, have a molecular weight of 24,000, a diameter of 2.6 nm, and a charge of -27. the positively charge ions (counterions) in this system are na".