Yurr wussup can someone help me with my questions on for science if nayones down put in the cmts . :)

The agent of mechanical weathering in which rock is worn away by the grinding action of other rock particles is call

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.

What is a number added in front of a formula in order to balance the equation