Describe the methods by which an electric potential develops in generators and thermocouple

What layer of the atmosphere is directly above the troposphere?

What is the mass defect of a mole of nuclei with 1.8 x 10^15 j/mol binding energy?

Voltaic cells produce a positive overall charge. what does this indicate? a. the reaction is likely to be endothermic. b. the reaction is spontaneous. c. the reaction is not likely to occur. d. the reaction is not spontaneous.