Which of the following statements is true concerning the electrochemical cell depicted below? Zn | Zn2+(aq) || Cu2+(aq) | Cu? Zn2+(aq) + 2e− Zn(s); E° = –2.87 V

Cu2+(aq) + 2e− Cu(s); E° = –2.38 V

a. The cell reaction is spontaneous with a standard cell potential of 0.49 V

b. The cell reaction is nonspontaneous with a standard cell potential of -0.49 V

c. The cell is at equilibrium

d. The cell reaction is spontaneous with a standard cell potential of 5.25 V

e. The cell reaction is nonspontaneous with a standard cell potential of -5.25 V

This line graph compares the growth of plants that were kept in the sun for different amounts of time.a)  on day 7, the plants kept in the sun for 3 hours were how tall? b)  on day 7, the plants kept in the sun for 6 hours were how tall? c)    on day 10, the plants kept in the sun for 9 hours were how tall? d)  on day 11, the plant that was grown with 1 hour of sunlight was how tall? e)  based on the graph, the plant grows best in what amount of sunlight?

Hot air balloons float in the air because of the difference in density between cold and hot air. in this problem, you will estimate the minimum temperature the gas inside the balloon needs to be, for it to take off. to do this, use the following variables and make these assumptions: the combined weight of the pilot basket together with that of the balloon fabric and other equipment is w. the volume of the hot air inside the balloon when it is inflated is v. the absolute temperature of the hot air at the bottom of the balloon is th (where th> tc). the absolute temperature of the cold air outside the balloon is tc and its density is ďc. the balloon is open at the bottom, so that the pressure inside and outside the balloon is the same. as always, treat air as an ideal gas. use g for the magnitude of the acceleration due to gravity.

The element that has the greatest electronegativity is