Which of these scenarios is most likely a chemical reaction?
1. a gas turns into a liquid as it releases energy.
2. a liquid becomes a gas as it absorbs energy.
3. two white solids are added to a colorless liquid, and a colorless liquid remains. 4. two colorless liquids are added together, and a colorless liquid and a green solid remain.

A3.37-mg sample of protein was chemically digested to convert its nitrogen into ammonia and then diluted to 100.0 ml. then 10.0 ml of this solution was placed in a 50-ml volumetric flask and treated with 5 ml of phenol solution plus 2 ml of sodium hypochlorite solution. the sample was diluted to 50.0 ml, and the absorbance at 625 nm was measured in a 1.00-cm cuvette and found to be 0.486. for reference, a standard solution was prepared from 10.0 mg of nh4cl (molar mass = 53.49 grams/mole) dissolved in 1.00 l of water. then 10.0 ml of this standard was placed in a 50-ml volumetric flask, treated in the same manner as the unknown, and the absorbance found to be 0.323. finally, a reagent blank was prepared using distilled water in place of unknown, it was treated in the same manner as the unknown, and the absorbance found to be 0.076. calculate the weight percent of nitrogen in the protein.

Ab c or d ? i’m not sure what the answer is

On the periodic table, elements are arranged by which of the following. a. mass numbers. b. increasing atomic number. c. alphabetical order. or d. density