Which of the following is the correct equation for the reaction below? One molecule of propane gas reacts with five molecules of oxygen gas to
form three molecules of carbon-dioxide gas and four molecules of water
vapor.
A. C3H8 (9) + 50 (g) → 3C0 (g) + 4H20 (9)
B. CH (g) + 502 (g) → 3C02 (g) + 4H0 (9)
C. C3H8 (s) + 502 (s)
3CO2 (s) + 4H20 (s)
D. C3H8 (9) + 502 (9)
3CO2 (g) + 4H20 (g)

Atown is considering building a biodiesel power plant that would burn biomass to generate electricity. which of the following correctly lists an advantage and a disadvantage of this project?

Aboxcar traveling at 12 m/s approaches a string of 5 identical boxcars sitting stationary on the track. the moving boxcar collides and links with the stationary cars and they all move off together along the track. what is the final speed of the cars immediately after the collision? (you may take the mass of each boxcar to be 18,537 kg.)

Some material consisting of a collection of microscopic objects is kept at a high temperature. a photon detector capable of detecting photon energies from infrared through ultraviolet observes photons emitted with energies of 0.3 ev, 0.5 ev, 0.8 ev, 2.0ev, 2.5ev, and 2.8ev. these are the only photon energies observed. (a) draw and label a possible energy-level diagram for one of the microscopic objects, which has four bound states. on the diagram, indicate the transitions corresponding to the emitted photons. explain briefly. (b) would a spring–mass model be a good model for these microscopic objects? why or why not? (c) the material is now cooled down to a very low temperature, and the photon detector stops detecting photon emissions. next, a beam of light with a continuous range of energies from infrared through ultraviolet shines on the material, and the photon detector observes the beam of light after it passes through the material. what photon energies in this beam of light are observed to be significantly reduced in intensity (“dark absorption lines”)? explain briefly.