Consider the following energy levels of a hypothetical atom:
-1.0 x 10^-19j
-5.0 x 10^-19j
-10 x 10^-19j
-15 x 10^-19j
(a) what is the wavelength of a photon needed to excite an electron from e1 to e4? (b) what is the energy (in joules) a photon must have in order to excite an electron from e2 to e3? (c) when an electron drops e3 level to the e1 level, the atom is said to undergo emission. calculate the wavelength of the photon emitted in this process.

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.

Which statement is usually true about the relationship between activation energy and reaction rates? low activation energy barriers result in low rates. high activation energy barriers result in low rates. low activation energy barriers result in no reaction. high activation energy barriers result in no reaction.

What is the main purpose of patent attorneys? defend the company against legal claims manage financial investments invent new products protect rights to new products and processes