X-ray diffraction is used to study the structure of crystallized proteins, nucleic acids, and other biological macromolecules. It was actually the technique used to study the structure of DNA in the early 1950s. X-rays of wavelength 0.20 nm are to used to study the structure of a protein. One of the maxima in intensity is located at 0.8 rad from the crystal planes responsible for this maximum.

PART A
Which wavelength of x-ray listed below would give you a maximum at the same location?
a. .26nm
b. .43nm
c. .34nm
d. .60nm

PART B
If this is the first maximum for the X-rays of wavelength 0.17 nm , what is the crystal plane separation of the protein that is responsible?
a. .12nm
b. .24nm
c. .17nm
d. .11nm

PART C
Why can't visible light be used to study the structure of proteins such as this?
a. Visible light reflects off of the surface of proteins.
b. Visible light does not have enough energy.
c. The wavelengths of visible light are too long compared to the atomic spacing.
d. The wavelengths of visible light are too short compared to the atomic spacing.

Suppose that recording station n is located 200 km north of the epicenter of an earthquake, and recording station s is located 100 km south of the epicenter of the same earthquake. which of the following statements would be true?

First, launch the video below. you will be asked to use your knowledge of physics to predict the outcome of an experiment. then, close the video window and answer the question at right. you can watch the video again at any point. part a as in the video, we apply a charge +q to the half-shell that carries the electroscope. this time, we also apply a charge –q to the other half-shell. when we bring the two halves together, we observe that the electroscope discharges, just as in the video. what does the electroscope needle do when you separate the two half-shells again? view available hint(s) as in the video, we apply a charge + to the half-shell that carries the electroscope. this time, we also apply a charge – to the other half-shell. when we bring the two halves together, we observe that the electroscope discharges, just as in the video. what does the electroscope needle do when you separate the two half-shells again? it deflects more than it did at the end of the video. it deflects the same amount as at end of the video. it does not deflect at all. it deflects less than it did at the end of the video. submit

Which additional product balances the reaction h2so4 + 2naoh → na2so4 + 2h2o 2oh h2o2 h3o