Which of these measurements was made with the most precise measuring device: 8.1956 m, 8.20 m, or 8.196 m? explain your answer.

Precision refers to the closeness of two or more measurements to each other. Like if one weigh a given thing five occasions, and achieve 3.2 kg each time, then the measurement is very precise. However, precision is autonomous of accuracy. One can be precise but inaccurate.  

In the given question, 8.1956 m is the most accurate measurement, as it is giving one the 10000th place of measurement.  

its 42

i say its d?

hydroxyl -oh

alcohols, always polar, can form hydrogen bonds with h2o molecules

carboxyl -cooh  

cargoxylic acids, has acidic properties which is a source of hydrogen ions, found in cells in ionized for with a charge of oh-1

carbonyl > co

ketone if within skeleton, aldehyde if group is at the end of skeleton, k & a may be structural isomers, it determines 2 sugars (ketose & aldose)

amino -nh2

amines, acts as a base, it can pick up h+ ions from surrounding solution, ionized with charge of 1+

methyl ch2

addition to rna/dna affects and gene expression

phosphate -opo3 ²⁻

organic phosphates, contributes to negative charge to, molecule that it is a part of, and potential to react with h20

sulfhydryl -sh

thiols, cross-linking stabilize the protein, and it is structure