51. Write a measurement of centimeters that has 3 non zero digits, two zeroes that are significant and one zero that is not significant

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.

The identities of substances are the same before and after which type of change

Covalent compounds: mastery test select the correct answer what is formed when atoms join together with a covalent bond? a. an ion b. a molecule c. a neutral atom d. a noble gas