Analytical chemists can detect very small amounts of amoin acids , down to 3x10^-21 mol. how many molecules of an amino acid (mr=200) would this be ?

What is the molarity of a solution that is prepared by adding 57.1 g of toluene (c 7 h 8 ) (density = 0.867 g/ml) to a 250 ml volumetric flask, and then filling to the mark with benzene (c 6 h 6 ) (density = 0.876 g/ml)?

Select the correct answer from each drop-down menu. daniel and sanya are scientists. daniel is studying whether the increasing frequency of tropical storms is affecting coastal erosion. sanya is investigating whether the discharge from industrial plants has any impact on the ph concentration of freshwater swamps in the surrounding area. which fields of science are daniel’s and sanya’s studies most closely related to? daniel’s field of study is related to science, and sanya’s field of study is related to .

The atomic radius of sodium is 186 pm and of chlorine is 100 pm. the ionic radius for na+ is 102 pm and for cl– is 181 pm. in going from na to cl in period 3, why does the atomic radius decrease while the ionic radius increases? a. the inner electrons in the sodium cation shield its valence electrons more effectively than the inner electrons in the chloride anion do. b. the inner electrons shield the valence electrons more effectively in the chlorine atom than in the chloride anion. c. the outermost electrons in chloride experience a smaller effective nuclear charge than those in the sodium cation do. d. the outermost electrons in chloride experience a larger effective nuclear charge than those in the sodium cation do. e. monatomic ions are bigger than the atoms from which they are formed.