Which is a general representation of a secondary amine? A. An N is bonded to two electron dots above; with a dotted triangular line to an H, a solid triangular line to an H, and single line to an H; it is noted that the angle between the last 2 H atoms is 107 degrees.

B. An N with 2 electron dots is linked to an R 1 group with a single line, an H with a triangular line, and and H with a dotted line.

C. An N with 2 electron dots is linked to an R 1 group with a single line, an R2 group with a triangular line, and and H with a dotted line.

D. An N with 2 electron dots is linked to an R 1 group with a single line, an R 2 group with a triangular line, and an R3 with a dotted line.
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1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false

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.

Find the mass in grams of 1.37x1020 particles of h3po4