The light beam shown in the figure below makes an angle of ϕ = 24.4° with the normal line NN' in the linseed oil. Determine the angles ? and ?'. (The refractive index for linseed oil is 1.48.) ? = __ ° ?' = __ °

There are two important isotopes of uranium, U235 and U238 ; these isotopes are nearly identical chemically but have different atomic masses. Only U235 is very useful in nuclear reactors. Separating the isotopes is called uranium enrichment (and is often in the news as of this writing, because of concerns that some countries are enriching uranium with the goal of making nuclear weapons.) One of the techniques for enrichment, gas diffusion, is based on the different molecular speeds of uranium hexafluoride gas, UF6 . (a) The molar masses of U235 and U238F6 are 349.0 g/mol and 352.0 g/mol, respectively. What is the ratio of their typical speeds vrms ? (b) At what temperature would their typical speeds differ by 1.00 m/s? (c) Do your answers in this problem imply that this technique may be difficult?

What is the density of 18.0-karat gold that is a mixture of 18 parts gold, 5 parts silver, and 1 part copper? (These value are parts by mass, not volume.) Assume that this is a simple mixture having an average density equal to the weighted densities of its constituents.

Find out the human population of Earth. Is there a mole of people inhabiting Earth? If the average mass of a person is 60 kg, calculate the mass of a mole of people. How does the mass of a mole of people compare with the mass of Earth?

Check Your Understanding The recommended daily amount of vitamin B3 or niacin, C6NH5 O2, for women who are not pregnant or nursing, is 14 mg. Find the number of molecule of niacin in that amount.

Estimate the number of molecules that make up Earth, assuming an average molecular mass of 30 g/mol. (Note there are on the order of 1024 objects per mole.)

What are two reasons why mercury rather than water is used in barometers?

Dry air consists of approximately 78% nitrogen, 21% oxygen, and 1% argon by mole, with trace amounts of other gases. A tank of compressed dry air has a volume of 1.76 cubic feet at a gauge pressure of 2200 pounds per square inch and a temperature of 293 K. How much oxygen does it contain in moles?

How large an expansion gap should be left between steel railroad rails if they may reach a maximum temperature 35.0 greater than when they were laid? Their original length is 10.0 m.

Pouring cold water into hot glass or ceramic cookware can easily break it. What causes the breaking? Explain Pyrex, a glass with a small coefficient of linear expansion, is less susceptible.