Abeaker with water and the surrounding air are all at 24°c. after ice cubes are placed in the water, heat is transferred from:
(1) the ice cubes to the air
(2) the beaker to the air
(3) the water to the ice cubes
(4) the water to the beaker

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.