A balloon contains two gases: oxygen and nitrogen. According to the second law of thermodynamics, which event can never occur spontaneously? A. molecules of the two gases mixing evenly throughout the balloon
B. molecules of the two gases leaking out small openings in the skin of the balloon
C. molecules of the two gases traveling at a variety of speeds
D. molecules of the two gases separating to opposite ends of the balloon

Acoal-fired plant generates 600 mw of electric power. the plant uses 4.8 x 10^6 kg of coal each day, and the heat of combustion of coal is 3.3x 10^7 j/kg. the steam that drives the turbines is at a temperature of 300° c, and the exhaust water is at 37° c. (a) what is the overall efficiency of the plant for generating electric power? (b) how much thermal energy is exhausted each day? (c) what is the change in entropy of the universe for this heat engine? (d) using the same heat reservoirs, what is the maximum possible (carnot) efficiency for a heat engine?

Which of the following elements is in the same period as phosphorus? a. carbon c. nitrogen b. magnesium d. oxygen select the best answer from the choices provided a b c d

Velocity is a description of both speed and direction, therefore it - a vector - a force arrow - the same as acceleration - a magnitude