Which statement describes a physical property related to the particles that make up a material?
A. Metallic bonds between tin ions cause a sheet of tin to be
malleable.
B. Gold ions in a piece of jewelry are resistant to combining with the
atoms of other elements.
C. Raindrops are moderately acidic when they combine with
molecules of air pollution.
D. A copper roof tile has a greenish color because copper ions
combine with atmospheric oxygen.

Using the periodic table, complete the table to describe each atom. type in your answers.a ? b? c? d? e? f?

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.

An observation that requires measurement is called quantitative observable or qualitative