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How many photons would be needed to produce 355 mJ of energy, if the photons have a frequency of 1.34 x 1029 s-1?

In order to receive credit for this problem you must   solve it using dimensional analysis  show all your work and   your work must be legible, well organized and easy to follow. to the correct number of significant figures Once Finished Show the work to the camera. Submit this Exam. Then go to the Free Response on Canvas take a picture and upload the answer.   Vanillin (used to flavor vanilla ice cream and other food) is the substance whose aroma the human nose detects in the smallest amount. The threshold limit is 5.00 x 10-11 grams per liter of air. If the current price of 50 grams of vanillin is $124, determine the cost to supply enough vanillin so that the aroma could be detected in a large aircraft hangar with a volume of 6.75 x109 ft3. (1 cm3=1 mL)     

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There are three natural isotopes for element L (L- 124, L-126, and L-127). Below are the atomic masses and percent abundances of element L. Determine the average atomic mass of the element.   L-124  123.9992 amu  22.101%  L-126  125.9909 amu  10.710%  L-127  126.9871 amu  67.189% 

 Which of the following experiments identifies a physical rather than a chemical property of a substance?

Below are the line spectra for Elements A-D and an unknown sample. What is the unknown sample composed of?

How many nanometers are in 256 cm?

How many cubic millimeters of silver have a mass of 0.0020 kg if the density of silver is 10.54 g mL-1? (1cm3 = 1mL)

Which of the following experiments identifies a physical rather than a chemical property of a substance?