1. Describe the movement of the particles in the air. 2. Choose two different particles found in the air. Explain how they are different and how they are the same.

3. Describe air using the terms: mixture, atoms, and molecules.

4. What is one source of CO2 ?

5. Describe the relationship between atoms and molecules.

6. Is the composition of air consistent? Explain your thinking.

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.