Two technicians are discussing using a refractometer to measure a battery's specific gravity. Technician A says that the refractometer reading is determined at the point of the scale where the dark and light areas meet. Technician B says that the reading is determined by where a dial points on a scale. Who is correct?

A-mn has a cubic structure with a0 0.8931 nm and a density of 7.47 g/cm3. b-mn has a different cubic structure, with a0 0.6326 nm and a density of 7.26 g/cm3. the atomic weight of manganese is 54.938 g/mol and the atomic radius is 0.112 nm. determine the percent volume change that would occur if a-mn transforms to b-mn.