How do you write a mathematical expression to demonstrate the relationship between the coefficient and the subscript I don't get it

How many moles are in 7.2 x 10^23 carbon molecules? (*round to the nearest hundredth and include the unit "mol c" after your number) question 6 options:

Define a is a tiny pavket of energy

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.