The tapeats sandstone and bright angel shale contain fossils of trilobites. trilobites were marine organisms similar to modern-day horseshoe crabs. no other layers contain trilobite fossils. which conclusion best explains these observations? a. the area became dry land after the bright angel shale period. b. an asteroid hit the earth after the bright angel shale period. c. the trilobites became extinct after the bright angel shale period. d. the trilobites migrated away from the area after the bright angel shale period.

Complete the following statements to describe solids, liquids, and gases. select the correct answer from each drop-down menu. a solid a definite volume and a definite shape. a liquid a definite volume and a definite shape. a gas a definite volume and a definite shape

At 20°c, a sample of h2o liquid and a sample of co2 gas each have the same average kinetic energy. why is one a liquid and the other a gas at this temperature?

)benzene and toluene form nearly ideal solutions. consider an equimolar solution of benzene and toluene. at 20 °c the vapour pressures of pure benzene and toluene are 9.9 kpa and 2.9 kpa, respectively. the solution is boiled by reducing the external pressure below the vapour pressure. calculate (i) the pressure when boiling begins, (ii) the composition of each component in the vapour, and (iii) the vapour pressure when only a few drops of liquid remain. assume that the rate of vaporization is low enough for the temperature to remain constant at 20 °c.