Would it make a difference if calcium bromide solution, cabr2, were used rather than sodium bromide solution?

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.

One student said that the investigation was not valid (a fair test). write a plan for the investigation that includes improvements to the method and apparatus

An atom holds 7 electrons. use orbital notation to model the probable location of its electrons. an atom hold 22 electrons. use orbital notation to model the probable location of its electrons. an atom holds 17 electrons. use orbital notation to model the probable location of its electrons.